Skip to main content

Full text of "A handbook of anatomy for art students"

See other formats


UNIVERSITY OF B.C. LIBRARY 




3 9424 05106 119 7 




rflH^^^^^HHj 


IHl 










^^^^^^^^^^^^^^^^^^^^^^^^^^^^■k I 



STO'RAGS ITE>! 
LIBRARY PROCESS 
ING 
Lp5-C04B 

U.B.C. UBRARY 



THE LIBRARY 




THE UNIVERSITY OF 
BRITISH COLUMBIA 



Digitized by the Internet Archive 

in 2010 with funding from 

University of British Columbia Library 



http://www.archive.org/details/handbookofanatomOOthom 



HANDBOOK OF ANATOMY 



FOR 



ART STUDENTS 



ARTHUR THOMSON 



OXFORD UNIVERSITY PRESS 

LONDON EDINBURGH GLASGOW NEW YORK 
TORONTO MELBOURNE BOMBAY 

HUMPHREY MILFORD M.A. 

PUBLISHER TO THE UNIVERSITY 



A 



HANDBOOK OF ANATOMY 



FOR 



ART STUDENTS 



CY 



ARTHUR THOMSON, M.A, F.R.CS., LL.D. 

PROFESSOR OF HUMAM AXATOMY IN THE UNIVERSITY OF OXFORD; PROFESSOR OF 

ANATOMY, ROYAL ACADEMY OF ARTS, LONDON; AND KATE LECTURER 

ON ANATOMY IN THE ROYAL COLLEGE OF ART 

SOUTH KENSINGTON 



WITH NUMEROUS ILLUSTRATIONS 



FOURTH EDITION 



OXFORD 
AT THE CLARENDON PRESS 

1915 



PR! X TED IN ENGLAND 
AT THE OXFORD UNIVERSITY PRESS 



DEDICATED 

TO THE 

MEMORY OF MY FATHER 

J O H x\ THOMSON, M.D. 

FLEET SURGEON, R.N. 



PREFACE TO THE FIRST EDITION 

The experience which I have had as a teacher and my 
acquaintance and sympathy with the requirements of 
students of Art have led me to the conclusion that hitherto 
too much stress has been laid on the nomenclature and 
technical details of Human Anatomy, and too little emphasis 
placed on the relation of these details to the surface forms. 
What the student requires is not a minute description of 
every bone, muscle, and joint, but only such an account 
as will enable him to appreciate their influence on the 
modelling of the figure. Names convey little to his 
mind, forms alone interest him. 

In the following pages, which are based on the lectures 
which I have had the honour of giving at the E-oyal College 
of Art, South Kensington, I have endeavoured to carry out 
as far as possible these principles. With this intention 
every effort hus been made to avoid unnecessary detail, and 
to rid the text as far as possible of technicalities. Where 
there are English equivalents for the scientific terms more 
commonly employed, they have been made use of; but 
unfortunately their number is limited, and the student is 
left with no other alternative than to accept the scien- 
tific nomenclature. 

In place of adopting, as is usual, the method of furnish- 
ing a complete description of the bones, succeeded by an 
equally detailed account of the joints and muscles, I have 
incorporated them in the description of regions. As each 
region — a limb for instance — is considered, its bones, joints, 
and muscles are described in so far as they have special 



viii Preface to the First Edition 

reference to the moulding of tlie surface forms. In this 
way it is hoped that the student may attain a better grasp 
of the subject than by the study of isolated descriptions ot 
the various structures involved. 

In order to cr.rry out such an idea it was necessary that 
the descriptions given should be supplemented by frequent 
reference to the model or by copious illustration. In the 
present work photography has been employed for this 
purpose. I am well aware of the drawbacks of such 
a method, yet it seems to me that these are counterbalanced 
l3y the truth of the resulting figures. The plates lay no 
claim to artistic excellence ; their value depends on their 
fidelity to nature. Artists, I feel sure, will sympathize 
with me in regard to the defects of some of the forms 
represented, knowing as they do how difficult it is to 
obtain universal excellence in a model. Apart from the 
professional models employed, I am largely indebted to 
some of the better known athletes of this University for 
the facilities which have enabled me to take the photo- 
graphs. For obvious reasons it is unnecessary for me to 
name these gentlemen, but I wish none the less to express 
my indebtedness to them. 

In the production of most of the keys which accompany 
the plates I have received much valuable assistance from 
my friend and pupil, Mr. Cecil W. Pilcher, B.A., of Keble 
College, who has also drawn a few of the illustrations in 
the text : to him my best thanks are due. For the rest 
of the figures I am alone responsible. Two or three have 
been borrowed from other sources, and in constructing the 
plates illustrative of the entire skeleton I have availed 
myself of the proportions laid down by the late Professor 
John Marshall, in his work entitled. A Rule of Proportion 
for the Human Figure. In the cuts with which the text 
is illustrated I have endeavoured to lay particular stress on 
those points which are of importance to the artist, and, 



Preface to the First Edition ix 

in spite of their shortcomings as drawings, I trust that 
they may appeal to the reader on account of their direct 
application to the subject-matter. 

K word or two as to how the subject should be studied. 
Let the student in the first place familiarize himself with the 
forms of the bones by rapid sketches of them in different 
positions. Especially is this necessary where the limbs are 
foreshortened. Having acquired this knowledge, let him 
then proceed to the study of the model. It is hoped that 
with the aid of the plates and their accompanying keys he 
will be able to determine for himself the form and position 
of the structures on which the surface contours depend. 
Assist the eye where possible with the hand, and by rapid 
and sudden changes of position ascertain precisely the 
nature of the underlying cause. 

In conclusion I have to thank Professor R. Howden, of 
the University of Durham, for the trouble and care which 
he has bestowed on the revisal of the proof-sheets, as well 
as for the many valuable hints he has given me. 



A. T. 



Oxford: 
August lo, 1896. 



PREFACE TO THE SECOND EDITION 

The reception accorded to the first edition of this book 
has been such as to lead me to believe that it has proved 
acceptable to that class of student for whom it is written. 
In it I endeavoured to explain, the principles which 
underlie the construction of the human figure, and hoped 
thereby to invest the subject with an additional interest, 
apart from its purely technical application. Conscious that 
the utility of such a work as this depends largely on its 
illustrations, I have in the present edition replaced some of 
the old figures by new blocks. Fourteen new plates have 
been added, and these, it is hoped, will be of service in 
throwing further light on the relation of muscular action 
to surface form. I wish I had possessed more technical 
skill to enable me to express in graphic form what one may 
term the ' Shorthand ' of the figure, for thereby no doubt 
many of the details referred to in this volume might have 
been better impressed on the memory ; on the other hand it 
is perhaps as well that the student should work out these 
details for himself in the life school. If in any way the 
present work serves to lighten his labours or proves an 
aid to his studies, I shall feel that my efforts have not been 
without reward. 

A. T. 

Oxford : 

Amjust I, 1899. 



PREFACE TO THE THIRD EDITION 

In preparing a new edition, the natural tendency is to 
amplify the text; under oidinary circumstances there may 
be no objections to such a course, but in a work such as this 
any considerable addition to the printed matter would be 
likely to defeat the purpose for which the book was in- 
tended. For that reason, I have limited the amount of 
new matter introduced, but have placed no such restrictions 
on the number of additional illustrations. In this edition, 
as far as the size of the book has permitted, the photographs 
have been reproduced on as large a scale as possible. A 
number of plates of the female figure, taken in positions 
closely resembling those in which the male models are 
represented, have also been introduced. In this way the 
comparison of the two types is rendered more easy, and it 
is hoped that the characteristic differences will thus be 
emphasized and so more forcibly impressed upon the 
student. 

In spite of opinion to the contrary, I have adhered to the 
plan of supplying the ' Key plates ' in semi-diagrammatic 
form ; what is wanted is not a detailed drawing of the ap- 
pearance of an 'Ecorche', but such an outline of the arrange- 
ment and disposition of the superficial parts as will at once 
enable the student to analyse the surface contours and 
realize the structures on which they depend. 

In an Appendix I have added three plates illustrative of 
students' work. I have done this, not only for the sake 
of my professional brethren who may be engaged in 
teaching Anatomy in Art Schools, but dlso as an indica- 



xii Preface to the Third Ed 

tion of the kind of knowledge the stude; 
acquiring. I am well aware that the stu( 
looked upon by many as useless and unpi 
experience as an Examiner has led me to 
a general acquaintance with the main f 
gain to the draughtsman, and of its a 
sculptor there can be no possible doubt. 

Oxford: 

Feh. 20, 1906. 



PREFACE TO THE FOURTH EE 

Recent improvements in the methods of ph^ 
reproduction have enabled the publishers to ma] 
advance in the illustration of this edition. The 
the work of the Rembrandt Intaglio Printing Con 
I have to thank that firm for the care and interest 
taken in the reproduction of my photographic sti 

Experience has led me to believe that mucl 
information may be derived from a direct com 
photographs of the two sexes. Whilst the br( 
differences are universally recognized, it is remai 
some of the finer distinctions escape notice. For t 
I have, as far as possible, supplied comparable il 
of fairly typical male and female models posed ir 
positions. If I have been unable to carry out tl 
all cases, the failure is due to the difficult}^ of gel 
factory models. Because of this, when such c 
plates are absent, as for example, the companioi 
that displayed on page 58, I must crave the ind 
my readers. 

There seems a notion about that anatomy for ai 
can only be taught from a model with pronouncec 
development. Now, nothing as a rule is more 



xiv Preface to the Fourth Edition 

Sucli photographic studies as I have utilized have been 
taken mainly from 'all round* university athletes, whose 
identity in the plates is of course disguised, but to whom 
I am none the less grateful. 

Little change has been made in the text, though some 
alterations have been introduced in the line blocks. 

I have further to express my thanks to Mr. F. W. Pomeroy, 
A.R.A., for much valuable advice in the choice of the plates, 
and to the Managers of the Regent Street Polytechnic for 
so kindly placing their photographic studio at my disposal. 

To many others I am indebted for help in the endeavour 
to obtain satisfactory models, and to the officials of the 
University Press I am under great obligations for their 
uniform courtesy and support in carrying out my every 
wish. 

ARTHUR THOMSON. 

Ocioher, 1915. 



CONTENTS 



CHAPTER I. 

THE INFLUENCE OF POSTURE ON THE FORM OF MAN. 

PAGES 

Eailj attempts at walking — Curves of back-bone— Vertebral column 
— Erectores spinae — Limb girdles — Pelvic girdle— Thigh-bone — 
Skeleton of lower limb— Leg and foot — Shoulder-girdle— Form 
of chest-wall— Skeleton of upper limb — Skull . . . 1-23 

CHAPTER IL 

GENERAL DESCRIPTION OF THE BONES AND JOINTS. 

Classification of bones — Chest-wall — Joints — Movable joints — 
Immovable joints 24-30 

CHAPTER in. 

VERTEBRAL COLUMN OR SPINE. 

Vertebral column — The vertebrae — Curves of column — Curves 
of back— Grooves for muscles —Erector spinae — Movements of 
column 31-55 

CHAPTER IV. 

THE THORAX, THE REGIONS OF THE FLANK, AND THE 
ANTERIOR ABDOMINAL WALL. 

Ribs — Breast-bone — Thorax — Anterior abdominal wall — Haunch- 
bone— Lumbar aponeurosis — External oblique— Rectus abdomi- 
nis — Contours of abdominal wall — Fold of groin — Differences be- 
tween male and female -The flank— Action of abdominalmuscles — 
Effect of movements on contours of abdominal wall . . 56-88 



xvi Contents 



CHAPTER V. 

THE SHOULDEK-GIRDLE AND THE MUSCLES WHICH 
INFLUEN'CE ITS MOVEMENTS. 

PAGES 

Shoulder-girdle— Collar-bone— Shoulder-blade— Girdle as a whole 

— Direct and indirect action of muscles — Trapezius— Rhomboids 

— Action of trapezius — Serratus magnus- Action of serratus 
magnus — Rotation of scapula — Humerus — Shoulder-joint — 
Latissimus dorsi — Pectoralis major — The breasts — Deltoid — 
Action of the deltoid — Infra-spinatus and teres minor -Teres 
major— Summary of the muscles of the back -The female back 89-144 

CHAPTER VI. 

THE UPPER ARM. 

The armpit — Coraco-brachialis — Humerus - Bonos of fore-arm — 
Ulna-Radius— Elbow-joint — Fascia of upper arm — Brachialis 
anticus — Biceps cubiti — Triceps — Anconeus — External inter- 
muscular septum— Internal intermuscular septum . . 145-177 

CHAPTER VII. 

THE FORE-ARM. 

Pionation and supination —^ Wrist-joint — Bonos of the wrist — 
Movements of the wrist-joint — Pronators and supinators — 
IMuscles of the fore-arm— Flexors of the wrist — Superficial flexor 
of the fingers — Supinator longus— Radial extensors — Ulnar exten- 
sor — Ulnar furrow - Common extensor of the fingers — Depression 
behind elbow— Extensors of thumb -Summary of muscles of fore- 
arm—Surface contours of fore-arm - Hollow in front of elbow 

— Influence of position on form of fore-arm -Contours around 
elbow- Superficial veins of arm —Front of wrist— Action of 
muscles 178-220 

CHAPTER VIII. 

THE HAND. 

Tiio skeleton of the hand -Joints of the fingers The thumb- 
Short muscles of the thumb — Abductor indicis— Muscles of the 
little finger - The palm The fingers — Back of the hand — 
IMovemcnta of thr' fingers - Summary. .... 221-242 



Contents 



xvn 



CHAPTER IX. 

THE GLUTEAL REGION. 

PAGES 

Skeleton of lower limb- Innominate bone — The ilium — Pubis — 
Sacrum — Pelvis — Femur— Obliquity of the thigh-bones — The 
hip-joint— Ilio-fenioral ligament— Mechanipm of erect posture — 
Obliquity of the pelvis— Influence of pelvic obliquity on thigh^ 
Movements of the hip-joint— Gluteus maximus- Gluteal fold 

— The buttock— Actions of gluteus maximus — Tensor fasciae 
femoris— Ilio-tibial band — Gluteus medius — Anterior superior 
iliac spine- Surface forms of buttock .... 243-279 

CHAPTER X. 

THE THIGH. 

The femur — Bones of the leg— The tibia— The fibula— The patella 

— Knee joint- Movements of knee-joint— Locking of the knee- 
joint— Muscles of the thigh— Extensor muscles — The vasti and 
rectus- Sartorius- Adductor muscles — Gracilis— Action of ad- 
ductors—Flexor muscles — The hamstrings - Action of the ham- 
strings— Form of female thigh - Hip width - Contours of thigh 

— Straightness of limb— Form of knee .... 280-319 

CHAPTER XI. 

THE LEG AND FOOT. 

Bones of leg— The ankle — Bones of the foot- Astragalus- Os calcis 

— Ankle-joint — Muscles of leg — Tibialis anticus— Long extensor 
of the toes— Peroneal muscles— Muscles ofcalf— Tendo Achillis — 
Action of muscles of calf — Surface contours of leg— The back 
of the knee — Form of leg in female — Bones of the foot — Arches of 
the foot — Dorsum of the foot— Short extensor of the toes— Muscles 
of the foot— Plantar fascia— Sole of the foot — The toes — Female 
foot— Superficial veins of leg 320-358 

CHAPTER XII. 

THE NECK. 

The atlas and axis -Movements of the neck — Muscles of the neck 

— Ligamentum nuchae — Deep stnictures of neck— Hyoid bone- 
Larynx- Thyroid body — Sterno-mastoid muscle— Pit of the neck 

— Hollows above the collar-bone — Action of sterno-mastoid — 
The platypma— Contours of neck— Length of neck— Movements 

of neck- Neck and (^boulders 359-383 

TuoMsos b 



xviii Contents 



CHAPTER XTII. 

THE HEAD. FACE. AND EXPRESSION. 



PAGES 



Tlie skull -Cones of the skull— Frontal sinus— Cranium -Size of 
h^ad— Bones of face— The facial angle— The lower jaw — The 
masseter — Form of lower jaw— The chin— The orbits — Nose — 
Ear— Mouth— Eyes — Expression — Muscles of expression — The 
eye in expression— Muscles of the nose -Muscles of the mouth — 
The mouth in expression -Laughter -Refl -ction -Shyness — Rage 
— Sneering -Disdain— Fear— Horror -Habitual expression 384-425 

CHAPTER XIV. 

PROPOETION. 

Proportion— Proportions of female— Female figure -Proportions 
of child - Growth— Old age and decay .... 426-4^6 

Appendix 447~45o 

Index ........... -1.^1-459 



PLATES 



PAGE 

Plate [ 8 

Male skeleton. Front view. 

Plate IT. 9 

Female skeleton. Front viev,-. 

Plate III 14 

Male skeleton. Back view, 

Plate IV 23 

Male skeleton. Side view. 

Plate V . . . , 34 

View of female back in eas}' position. 

Plate VI and Key Plate 34 

View of male back in easy position. 

Plate VII 36 

View of female back. 

Plate VIII and Key Plate 38 

Fig. I. Back view of male throwing a spear. 
Fig. 2. Front view of male throwing a spear. 

Plate IX and Key Plate . .44 

View of male back with arm uplifted supporting a weight. 

Plate X and Key Plate 50 

Back view of male figure bending forward and pulling on 
a strap. 

Plate XI 52 

Back view of female figure inclined to the side and lifting ajar. 

Plate XII and Key Plate 52 

Back view of male figure inclined to the side and lifting 
a weight. 

Plate XllI .54 

Side view of female figure rotated from speclator. 

Plate XIV and Key Plate .54 

Side view of male figure rotated from spectator. 

Plate XV and Key Plate ' . . • 58 

Front view of male trunk in easy position. 

Plate XVI and Key Plate 62 

Front view of youthful male figare with arms uplifted. 



XX Plates 

PAGE 

Plate XVII ^^ 

Front view of female figare inclined to the side and lifting ajar. 

Plate XVIII and Key Plate 72 

Front view of male figure inclined to the side and lifting 
a weight. 

Plate XIX Co 

View of female figure resting Dn the ground. 

Plate XX 86 

Side view of female figure turned towards the spectator. 

Plate XXI and Key Plate .86 

Side view of male figure turned towards the spectator. 
Plate XXII and Key Plate 94 

View of male back with arm raised to a right angle. 
Plate XXIII and Key Plate 98 

View of male back with arm raised above the head. 
Plate XXIV and Key Plate 104 

Side view of seated male figure. 

Plate XXV . no 

Fig. I. View of female back with shoulders forward. 

Fig 2. View of female back with shoulders drawn back. 
Plate XXVI and Key Plate no 

Fisr. I. View of male back with shoulders forward. 

Fiff 2. View of male back with shoulders drawn back. 
Plate XXVII and Key Plate .122 

Fiir. I. Side view of male trunk with arm raised to a right 
angle. 

Fig. 2. Side view of male trunk with arm raised above the head. 

Plate XXVIII 124 

Side view of seated female with arms raised above the head. 

Plate XXIX and Key Plate 126 

Three-quarters view of male back with arm uplifted. 

Plate XXX 132 

Fig. I. Front view of female bust. 

Fiff. 2. Front view of female bust with one arm raised. 

Plate XXXI and Key Plate 138 

Fii?. I. View of male back with shoulders drawn forwards. 
Fig. 2. View of male back with shoulders drawn back. 

Plate XXXII 142 

Fig. 1. Three-quarters back view of female trunk witli right 

arm uplifted. 
Fig. 2, IJack view of same model with both hands raised behind 

the liead. 



Plates , xxi 

PAGE 

Plate XXXIII and Key Plate 148 

Front view of male trunk with riglit arm raised to a right angle. 

Plate XXXIV and Key Plate 152 

Three-quarters front view of male trunk with the left arm 
raised to the side of the head. 

Plate XXXV and Key Plate 158 

Fig. I. Front view of female trunk with both arms extended 

above the bead. 
Fig. 2. Front view of male trunk with both arms extended 

above the head. 

Plate XXXVI and Key Plate 162 

Side view of male trunk with the left arm outstretched, striking 
a blow. 

Plate XXXVII and Key Plate 170 

Front view of extended arms. 
Fig. I. Prone. 

Fig. 2. Midway between the prone and the supine positions. 
Fig. 3. Suj)ine. 

Plate XXXVIII 176 

Fig. I. Fore-arm bent on raised upper arm. Inner view. 
Fig. 2. Fore-arm bent on raised upper arm. Outer view. 

Plate XXXIX and Key Plate 182 

View of male back with bent arm raised to a right angle. 

Plate XL and Key Plate - 200 

Back view of extended arms. 
Fig. I. Prone. 

Fig. 2. Midway between the prone and supine positions. 
Fig. 3. Supine. 

Plate XLI and Key Plate 212 

Fig. I. Bent arm with fore-arm supine. Inner view. 
Fig. 2. Bent arm with fore-arm supine. Outer view. 

Plate XLII .216 

Fig. I. Front view of female lower limbs, muscles relaxed. 
Fig. 2. Front view of female lower limbs, muscles contracted. 

Plate XLII I and Key Plate 216 

Fig. I. Front view of male lower limbs, muscles relaxed. 
Fig. 2. Front view, of male lower limbs, muscles contracted. 

Plate XLIV 252 

Profile view of female lower limbs with left leg raised and knee 
bent at a riorht anirle. 



xxii Plates 

PAGE 

Plate XLV and Key Plate 252 

Profile view of male lower limbs with left leg niised and knee 
bent at a right angle. 

Plate XLVI 262 

Profile view of female figure with arms outatretched at a right 
angle. 

Plate XL VII 268 

' Back view of female lower limbs. 

Fig. I. With both legs straight and supporting equally the 

weight of the trunk. 
Fig. 2. With the left knee slightly bent and the right leg 
straight. 

Plate XLVIII 270 

Three-quarters back view of a female figure with the left hand 
resting on the head. 

Plate XLIX . , 274 

Views of female legs in kneeling position. 

Fig. I. With left knee on the ground and right knee bent to 

a right angle. 
Fig. 2. With right knee on the ground and left knee bent to 
a right angle. 

Plate L and Key Plate 274 

Views of male legs in kneeling position. 

Fig. I. With left knee on the ground and right knee bent to 

a right angle. 
Fig. 2. With right knee on the ground and left knee bent to 
a right r„ngle. 

Plate LI 278 

Three-quarters back view of a female figure supported by 
a staff. 

Plate LH 298 

Front view of a female figure carrying a jar. 

Plate LIII ^08 

Side view of a female figure seated on the ground. 

Platk LIV 318 

Profile view of lemalc lower limbs with right leg raised and 
knee bent at a right angle. 

Plate LV and Key I'late 318 

i'rofih; vii'wof male lower limbs with right leg raised and knee 
bent at a rifrht ani^le. 

I'late LVI and Key Plate 328 

Fig. r. I''i()i)t f)!' right leg and foot (male). 
Fig. 2. iiaclc of right leg and foot (male). 



Plates xxiii 

PAGE 

Plate LVII 338 

Female lower limbs in tbe act of walking-, with left leg- 
advanced, , 

Tlate LVIII and Key Plate 338 

Male lower limbs in the act of walking, with left leg advanced. 

Plate LIX - 366 

Female lower limbs in the act of walking, with right leg 
advanced. 

Plate LX and Key Plate 366 

Male lower limbs in the act of walking, with right Xo^"^ 
advanced. 

Plate LXI and Key Plate 382 

Front view of a male figure stooping forward and lifting 
a weight. 

Plate LXII . 410 

Fig. I. Muscles of the face and neck. Front view. 
Fig. 2. Muscles of the face and neck. Side view. 

Plate LXIII 428 

Proportions of the male and female figure in heads and half- 
heads. 

Plate LXIV 434 

Front view of female figure with uplifted right arm. 

Plate LXV 434 

Front view of male figure with uplifted right arm. 

Plate LXVI 438 

Side view of female figure turned towards the spectator. 



ANATOMY FOR ART STUDENTS 

CHAPTER I 

THE INFLUENCE OF POSTURE UPON THE FORM OF MAN 

' Man alone stands erect.' The least observant amongst 
us cannot have failed to recognize the fact that man owes 
much of his dignity to the erect posture. In this respect 
he differs from all other animals. If we compare him with 
the man-like apes, his near relations, they suffer much by 
contrast. The gait of these creatures is shuffling, and the 
balance of the figure unsteady ; while their whole appear- 
ance, when they attempt to walk upright, suggests but a 
feeble imitation of the grace and dignity of man's carriage. 

The assumption by man of the erect position has led 
to very remarkable changes in the form of his skeleton and 
the arrangement and development of his muscles. 

In his growth from the ovum to the adult, he passes 
through many stages. In some of these his ascent from 
lower forms is clearly demonstrated. This statement holds 
good not only in regard to structure, but also as regards 
function. 

To take a case in point. The child at birth is feeble and 
helpless, and the limbs are as yet unsuited to perform the 
functions they will be called upon to exercise when fully 
developed. Dr. L. Robinson has clearly proved that the 
new-born child possesses a remarkable grasping power in 
its hands. He found that infants, immediately after birth, 
were able to hang from a stick, for a short time, by clutching 



2 Early Attempts at Walking 

it with the hands. With this exception, we may regard 
the movements of the limbs as ill controlled and imperfect. 
At first the legs are not strong enough to support the body. 
It is only after a considerable time has elapsed that the 
child makes efforts to use them as means of progression. 
These first attempts are confined to creeping, an. act in which 
the fore limbs play as important a part as the hind. With 
advancing age, however, the legs become longer and the 
muscles more powerful. In course of time they are suffi- 
ciently strong to support the body- weight. In the earlier 
stages of the assumption of the erect posture the child 
assists itself by laying hold of any object which it can conve- 
niently grasp with its hands ; as yet its efforts are ungainly 
and unsteady, but practice, and the exercise of a better 
control over the muscles of the legs, soon enable it to stand 
upright and walk without the aid of its upper limbs. 

There are thus three stages in the development of this 
action : first, the use of ' all fours ' ; secondly, the emplo}^- 
ment of the upper limbs as means to steady and assist the 
inadequately developed lower limbs — this mode of pro- 
gression is comparable to that of the man-like apes ; and, 
thirdly, the perfected act wherein the legs are alone suffi- 
cient to support and carry the body. 

The growth and development of the legs are not the 
only changes that are associated with the assumption of the 
erect position. If the back-bone of an infant at birth be 
examined and compared with that of an adult, other differ- 
ences than those of size and ossification will be observed. 
As will be afterwards explained, the adult back-bone is 
characterized by certain curves, some of which we fail to 
notice in the child. These latter, therefore, are developed 
at a period subsequent to birth, and are described as 
secondary curves, whilst those which exist at birth and 
are maintained throughout life are called primary, curves. 
The primary curves are those associated with the forma- 



Curves of Back-bone 3 

tion of the walls of the great visceral cavities, whilst 
the secondary curves are developed coincident with the 
assumption of the erect position, and are compensatory in 
their nature. The advantage of this arrangement is that 
the curves are not all bent in the same direction, but 
alternate, so that the column is made up of a succession 
of backward and forward curves. In this way the general 





Fig, I. Diagram to show Fig. 2 displays the curves 

the curves in the back-bone in the back-bone of the 

of an infant. adult. This figure has been 

reduced to the same size as 
Fig. I so as to render com- 
parison easier. 

direction of the back-bone is vertical, which it could not 
possibly be if the curves did not so alternate, for then all 
the curves would be directed forwards, *and a vertical line 
would fall either in front of, across, or behind the bent 
column in place of cutting it at several points, as happens 
in the column with the alternating curves. This becomes 
a matter of much importance when the vertical line coin- 

B 2 



4 Curves of Back 

cides with the direction of the force exercised by gravity, 
as in standing upright. 

These facts may be proved by looking at a baby. The 
back displays a uniform curve from the shoulders to 
the hips ; as soon as the child begins to walk, however, 
the development of a forward curve in the region of the 
loins is observed, a curve which ultimately becomes per- 
manent and is associated with the graceful flowing contours 
which are characteristic of the back of the adult. This 
lumbar curve is one of the most remarkable features of man's 
back-bone, for, although the curve is exhibited to a slight 
extent in the columns of the apes, in none does it approach 
anything like the development met with in man. On the 
other hand, in four-footed animals, where the column is 
horizontal in position, there is either no such curve present, 
or it is only slightly developed. 

The assumption of the erect posture necessarily involves 
the growth of powerful muscles along the back to uphold 
and support the back-bone and trunk in the vertical 
position, as is proved by the changes which take place 
in old age. At that time of life the muscular system 
becomes enfeebled, and is no longer strong enough to 
hold the figure erect ; the consequence of which is the. 
bent back and tottering gait of the aged, who, in their 
efforts to avail themselves of every advantage, seek the 
assistance which the use of a staff affords. Thus history 
repeats itself within the span of our own existence. It has 
been seen how the young child avails itsQlf of the assistance 
of its upper limbs in its first attempts to walk ; and it is 
noteworthy how, in that ' second childhood', the weak and 
aged seek additional support by the use of their arms 
and hands. 

It is, however, to neither of these types that our attention 
must be especially directed, but rather to the examination 
of inmi- in the full exercise of his strength, after he has 



Vertebral Column 5 

outgrown the softness and roundness of youth, and before he 
has acquired any of the weakness dependent on advancing 
years. 

Starting, then, with the fundaraental idea that the erect 
posture is essentially a characteristic of man, it is necessary 
to study in some detail the various modifications in his 
bony framework and muscular system which are associated 
with this posture. 

As a vertebrate animal, man possesses a hack-hone or 
spinal column made up of a series of bones placed one above 
the other. Around this central column are grouped the 
parts of the skeleton which protect and support the trunk. 
On the upper end of this axis is poised the head, and 
connected with the trunk are the two pairs of limbs — the 
arms and legs. 

For convenience of description it will be necessary to 
consider the body in its several parts : 

(i) The trunk. 

(2) The lower limbs. 

(3) The upper limbs. 

(4) The head and neck. 

In regard to the trunk, as has been already stated, the 
vertehral column, so called because it is composed of a 
number of separate bones or vertehrae, forms the central 
axis around which the other parts are grouped. Comparing 
the position of this chain of bones in man with that 
observed in a four-footed animal, it will be noted that in 
man its axis is vertical, whilst in a quadruped it is more 
or less horizontal ; moreover, the column in man is curved 
in a more complex manner than is the case in animals. 
It is on these curves that the column is mainly dependent 
for its elasticity. It would, however, be unable to sustain 
the weight of the trunk unless some provision had been 
made whereby it could be held erect. This is supplied 
by the powerful groups of muscles which lie in the grooves 



6 Eredores spinae 

on either side of, and behind, the back-bone. An inspection 
of the back of a model will enable the student to recognize 
these fleshy masses on either side of the middle line, 
particularly in the lower part of the back, in the region of 
the loins. These groups of muscles are called the eredores 
spinae, a name which sufficiently explains their action. 
How much depends on the action of these muscles is, as 
has been said, amply demonstrated in the case of the feeble 
and aged, in whom the muscles are no longer able properly 




Fig. 4. 



Fig. 3. 



Figs. 3, 4 (after Goodsir) show 
the characteristic differences in the 
arrangement of the parts of the 
skeleton in man and a quadruped. 



to perform their function, with the result that the persons 
so affected are unable to hold themselves erect for any time 
without fatigue. 

The column supports the weight of the head, and by its 
connexion with the ribs, enters into the formation of the 
chest'Wall. The upper limbs are connected with the chest- 
wall in a way which will be subsequently described. It 
is thus evident that this central axi^ls'a mosfc\mportant 
factor in the formation of the skeleton of the trunk. Throuirh 
it ttie entire weight of the head, upper limbs, and trunk is 



.♦-'- 



^^ 



Limb Girdles 



7 



transmitted to the lower limbs, which necessarily have to 
support their combined weight in the erect position. 

It is to the structure of these limbs that our attention 
must next be directed. In considering 
them it must be borne in mind that 
the legs serve two purposes : first, they 
afford efficient support, and, secondly, 
they are adapted for the purposes of 
progression. The limbs are connected 
with the trunk by means of bones 
arranged in a particular way. These 
are termed 'the limb girdles. There 
are two such gi-rdles — the shoulder- 
girdle^ connecting the upper limbs with 
the trunk, and the pelvic girdle, con- 
necting the lower limbs with the trunk. 
As the latter is concerned in transmit- 
ting the weight of the trunk to the lower 
limbs, it is well first to examine it. 

From its function it is essential that 
the pelvic girdle should be firmly 
united to the vertebral column or 
central axis by means of an immovable 
joint. In order to effect this union the 
segments or vertebrae, of which the 
column is made up, undergo certain 
modifications in the region where the 
girdle-bones of the lower limb are 
attached. This modification consists 
in the fusion of a number of these 
vertebrae, which are separate in the 
infant, and their conversion into one 

large wedge-shaped bone called the sacrum. This bone, 
built up by the union of five vertebrae, is, in man, remark- 
able for its width and stoutness. It acts not only as a strong 




Fig. 5. A diagram 
to show the arrange- 
ment of the muscles 
which support the 
back-bone. The mus- 
cles, which are repre- 
sented in solid black, 
are seen to be thick 
in the regions of the 
loins and neck, and 
comparatively thin in 
the mid-dorsal region. 



8 




WALK SKELETON, FRONT VIEW 




FEMALE SKELETON, FRONT VIEW 



lO 



Pelvic Girdle 



connecting link between the vertebral column and the bones 

of the pelvic girdle with 
which it articulates, but also 
provides a fixed base on 
which the upper and mov- 
able segments of the central 
axis are placed. The pos- 
terior aspect of the sacrum 
also furnishes an extensive 
surface for the attachment of 
the erector muscles of the 
spine, which assist so materi- 
ally in maintaining the 
column in its erect position. 

The bones of the pelvic 
girdle, though separate at an 
early period of life, are in 
thd process of growth fused 
together to form a large 
stout irregular bone called 
the haunch-hone (os Innomi- 
natum). There are two such 
bones— one for either limb — 
and these are united behind 
to each side of the sacrum 
by means of an immovable 
joint. The girdle is further 
strengthened by the union of 
the two bones with each other 
in the middle line in front, 
where they are bound to- 
gether by an immovable joint 
called the symphysis pubis. 
A bony basin, called the 
the articulation of these two 




Fig. 6. The back-bone and pelvis. 

a. Includes the twenty-four movable 

vertebrae. 

b. Is placed on the sacrum and coccyx, 

made up of five vertebrae each, 
which are fused together ; the 
sacrum articulates with 
e. The haunch-bone (os innominatum), 
on the outer side of which at 

c. Is the80cket(acetabulum)for the recep- 

tion of the head of the thigh-bone. 

d. The pubic arch and symphysis pubis. 

pelvis, is tlius formed by 



k 



Pelvic Girdle ii 

liauncii-bones in front, and their union with the sacrum 
behind. There is no movement between the several parts 
of this osseous girdle, and it is firmly united with the lower 
part of the vertebral column. It helps to form the lower 
part of the trunk, and, by its expanded surfaces, assists 
materially in supporting the abdominal contents. This 
form of pelvis is very characteristic of man. As a result 
of the assumption of the erect posture the abdominal viscera 
are no longer supported entirely by the abdominal walls, 
as in four-footed animals, but rest to a very consider- 
able extent on the expanded wings of the pelvic bones. In 
addition, the outer surfaces of 
these expanded plates of bone 
are utilized to provide attach- 
ment for the powerful muscles 
which pass from and connect 
this pelvic girdle with the 
thigh-bone, a group of muscles 
which in man attains a remark- Fig. 7. A diagrammatic repre- 
able development. sentation of the pelvic girdle. 

The fact must be emphasized 5.' Hau'^^-bone (os innominatum). 

that no movement is possible ^- Sy^^pi^ysis pubis. 

d. Upper end of thigh-bone (femur). 

between the pelvic girdle and 

the sacrum, and that all the weight transmitted down the 
vertebral column through the sacrum is equally distributed 
between the two haunch-bones. 

If the outer surface of each of these bones be examined, 
a deep cup-shaped cavity will be noticed, into which the 
rounded head of the thigh-bone or femur fits, thus 
forming the movable articulation called the hip-joint. 
The bones of the thigh and leg are remarkable for their 
length ^ Combined they equal in length the measurement 
of the head and trunk. This relative development is not 

' The terms ' thigh ' and ' leg ' are applied respectively to the parts of 
the limb above and below the knee. 




12 



Thigh-bone 



attained by any other animal. In addition, the thigh-bone 
of man possesses an extremely long and well-marked neck. 
The neck is that part of the bone which supports the 
rounded articular head, and connects it in an oblique 
direction with the upper end of the shaft. The length 
of the neck of the femur is peculiar to man, and permits 
a freedom of action of the limb not attainable by any 
other animal, the movements in the lower animals being 
more or less limited to a backward and forward direction. 
By means of the neck of the thigh-bone we have in man 
an arrangement which fulfils all the conditions necessary 
to ensure stability, and permits a more extended range 
of movement, not only from before backwards and from 
side to side, but also in an inward and outward direction. 
This latter is the movement of rotation, whereby we are 
enabled to turn the front of the limb inwards or outwards 
as desired. 

The muscles to which reference has been already made in 
connexion with the outer surfaces of the haunch-bones are 
inserted into the upper part of the thigh-bone. As they 
are immediately concerned in the control of certain impor- 
tant movements of the hip-joints, through which the entire 
weight of the trunk is transmitted to the lower limbs, they 
necessarily acquire a very great development, a develop- 
ment on which is dependent the prominence of the 
buttocks. This appearance was justly regarded by Aris- 
totle as eminently characteristic of man. 

The thigh-bones, separated above by the width of the 
pelvis, are placed obliquely so that they lie side by side 
in the region of the knees. 

The bones of the leg are two in number. They are 
immovably united to each other, since any movement 
between them would interfere with their stability and 
thus weaken the limb as a means of support. One only 
of these bones, the shin-bone or iibiaj enters into the 



'J / 



Skeleton of Lower Limb 



^3 





Bones of the lower limb. 

Fig. 8. Front view. Fig. 9. Side view. 

The lettering is the same in both figures. 

a. Sacrum. d. Knee-pan (patella). 

h. Haunch-bone (os innominatum). e. Fibula, 

c. Thigh-bone (femur). /. Shin-bone (tibia). 

g. Bones of foot (tarsus, &c,). 



H 




MALE SKELE.TON, BACK VIEW 



Leg and Foot 15 

formation of the knee-joint ; by its expanded upper ex- 
tremity it affords a broad surface not only for the support 
but also for the movements of the condyles, or articular 
surfaces, of the thigh-bone. The slender outer bone, 
the fibula, furnishes extensive attachments for numerous 
muscles. 

The fleshy masses which move the leg on the thigh at 
the knee-joint clothe both the front and back of the thigh- 
bone ; in man the extensor group of muscles, viz. that 
placed on the front of the thigh, which extends or 
straightens the leg, attains a relatively greater develop- 
ment than the flexor group, which is situated on the back 
of the limb. This is just the reverse of what is found 
in animals, and is associated in man with the power he 
possesses of bringing his leg into a direct line with his 
thigh, that is to say he can straighten or extend his limb 
at the knee-joint in a way which no other animal can 
effect. 

Man's foot is a very characteristic member. It possesses 
the qualities essential to strength and solidity combined 
with elasticity and movement. When standing upright 
the axis of the foot is placed at right angles to the axis 
of the leg. 

The bones which enter into the formation of the foot 
are disposed so as to form a series of arches. The advantage 
of this arrangement is that the soft parts on the sole are 
protected from pressure, while at the same time considerable 
elasticity is imparted to the foot. The slight play of the 
bones which form the arches allows the latter to act like 
a series of curved springs. 

The form of the heel-bone, or os calcis, is characteristic : 
to its posterior part is attached that group of muscles which 
determines the form of the calf. The development of these 
muscles is very great ; and it is noteworthy that they are 
quite typical of man, as no animal equals him in this 



1 6 Foot 

respect. This is explained by the fact that not unfrequently 
they are called upon to support the entire weight of the 
body, as in the acts of standing or dancing on tiptoe, while 
at other times they are required to project the body 
forward, as in springing or leaping. 

The bones of the toes are shorter than those of the 
fingers. The great toe is united to the others and lies side 
by side with them ; it has ho such power of separation and 
closing on the other toes as is possessed by the thumb. 
Thus the stability of the foot is not interfered with by 
an excess of mobility such as we see in the apes, where 
this power of movement is necessary. In them the foot is 
employed as a grasping organ, a modification which greatly 
assists the animal in its arboreal habits. 

From what has been stated it will be apparent that the 
lower limb of man displays in its structure those modifica- 
tions which are essential to the combination of support and 
mobility. 

In the upper limb, the same influences lead to modifica- 
tions in its structure which enhance its usefulness. As 
already stated, the child dispenses with the use of his arms 
as aids to progression as soon as his legs become strong 
enough to support him. This relieves the upper limb of 
one function, and permits a development of that member 
rather in thp direction of freedom of motion. So, extensive 
is the range of movement of this limb that man can touch 
any part of his body with one or other hand. 

An examination of the bones of the shoulder-girdle — the 
bones by which the upper limbs are connected with the 
trunk — at once reveals a remarkable difference between 
their mode of articulation with the skeleton of the trunk 
and that which has been already described in connexion 
with the pelvic girdle. 

The shoulder-girdle consists of two bones on either side, the 
collar-hone or clavicle^ and the shoulder-hlade or scapula. 



Shoulder-girdle 17 

These two bones are united by a small joint which permits 
limited movement in certain directions, but the girdle 
is only connected with the skeleton of the trunk by one 
joint on either side, viz. that between the upper end of the 
hreast-hone or sternum and the inner extremity of the collar- 
bone. The range of movement of this joint is not extensive. 
The shoulder-blade, on the other hand, is not directly con- 
nected with the skeleton of the trunk, but only indirectly, 
through its articulation with the collar-bone. At the same 
time the blade-bone is attached by numerous muscles to 
the framework of the chest- wall. By this means, though the 
range of movement in the two joints just named is limited, 
the combination of these movements and the looseness of 
the connexion of the shoulder-blade with the chest-wall 
impart a very extensive range of movement to the entire 
girdle. When it is remembered that this girdle is arti- 
culated with the bone of the upper arm, the student will 
recognize how important a part it plays in increasing the 
freedom of movement of the upper limb. 

As has been shown, the shoulder-girdle in man is modified 
in order to increase the range of movement of a limb used 
for prehensile purposes, and this is correlated with an 
alteration in the form of the chest-wall. In animals in 
which the fore limb is used as a means of suj^port, the form 
of the chest-wall is laterally compressed, that is to say the 
depth of the chest cavity is greater than its width. In man, 
on the other hand, in whom the limb is not habitually made 
use of to uphold the trunk, the chest- wall, relieved from 
pressure, expands laterally ; hence the thoracic or chest 
cavity is wider from side to side than from before back- 
wards. 

The joint between the shoulder-girdle and the upper 
extremity of the humerus, or bone of the upper arm, requires 
a brief description. The union of the limb bone with the 
girdJe is effected by means of a relatively small shallow 

tHOMSOM Q 



i8 



Shoulder-girdle 



socket on the shoulder-blade in which the large rounded 
head of the humerus rests. The fibrous bands, called liga- 
ments, which surround this joint are lax, so that they limit 




Fig. io. Bones of the ijglit upper limb, front view. 



a. Collar-bone (clavicle). 
h. Breast-bone (sternum). 

c. Shoulder-blade (scapula).* 

d. Humerus. 



e. Radius. 
/. Ulna. 

q. Wrist-bones (carpus). 
h. Metacarpus. 



i. Finger-bones (phalanges). 

but slightly the range of movement possible. This is in 
striking contrast to what we have seen in the articulation 
of the hip, where the hollow for the reception of the head 



Shoulder-girdle 



19 



of the thigh-bone is deep and surrounded by a prominent 
margin. A moment's consideration will at once explain the 
difference in the nature of the two joints. The shoulder- 




FiG. IT. Bones of the right upper limb, back vicv 



a. Collar-bone (clavicle). 

c. Shoulder-blade (scapula). 

d. Humerus. 

e. Radius. 



/ Ulna. 

g. Wrist-bones (carpus). 
Ti. Metacarpus. 
i. Finger-bones (phalanges). 



joint is adapted to permit very free movement, and is, 
relatively speaking, a weak joint, as demonstrated by the 
frequency with which it is dislocated, whilst the hip-joint 



c 2 



20 Skeleton of Upper Limb 

combines great strength with a more limited range of 
movement. 

There arc two bones in the fore-arm as in the leg, but, 
whilst in the latter the bones were seen to be immovably 
united, in the fore-arm the bones are jointed together in 
such a manner as to move freely on one another in certain 
definite directions. The resulting movements are termed 
pronation and supination, and are effected by the rotation 
of the outer bone or radius over the inner bone or ulna. 
These movements, not confined to man, but found in those 
animals whose fore-limbs are used for prehensile purposes, 




Fig. 12. Diagrammatic representation of the 
shoulder-girdle. 
a. First dorsal vertebra. d. S.houlder-blade (scapula). 

h. First rib. e. Collar-bone (clavicle). 

c. Breast-bone (sternum). /. Humerus (bone of upper arm) 

are extremely serviceable and greatly enhance the value 
of the hand as a grasping and tactile organ. 

The terminal segment of the human upper limb is 
marvellously adapted for performing the most delicate mani- 
l>ulat ions. Man has been defined as a * tool-using ' animal, 
■M\(\ no (]f»nl)t owes much of his supremacy to the facility 
wlii'li Ir. j)osscsses of 'turning his hand' to almost any- 
tliirig. This power he owes largely to the freedom of 
njovomfjnt and power of opposition of the thumb, the most 
u.soful, as it is the most important in regard to size and 
strength, of all <he digits. 

Tho /jX'm// must now be considered: this consists of two 
portions one which encloses the brain, the other which 
supports and ])rotects the soft parts of the face. If the 



Skull 



21 



liuman skull be compared with that of a man-like ape, it 
will be observed that the development of that portion 
which contains the brain in man is far in excess of the 
corresponding part in the anthropoid. In the latter the 
bones of the face are always more prominent, forming 
the projection which is familiarly known as the muzzle, 
whilst in man the face underlies the expanded brain-case, 
and projects but slightl}^ in front. This difference gives 
rise to modifications in the manner in which the head is 





Fig. 13. Skull and cervical ver- 
tebrae of a gorilla, showing pro- 
jecting muzzle, small brain-case, 
and elongated cervical spines. 



Fig. 14. Skull and cervical 
vertebrae of man, showing 
small face-bones, large brain- 
case, and short cervical spines. 



supported on the vertebral column. In a dog the skull 
is slung at the anterior extremity of a more of less 
horizontal spinal column ; in man the head is poised on 
the upper end of a vertical column ; whilst in the man-like 
apes an intermediate condition is observed, the column 
here being more or less oblique in direction. Owing to 
the fact that in quadrupeds and apes the muzzle is very 
large, special provision, in the form of an elastic ligament, 
is necessary to assist in supporting the head. In man, 
however, the parts are so distributed, owing to the absence 



22 



Skull 



of muzzle and the greater development of the back and 
upper part of the head, that the skull, when placed upon 
its articular surfaces on the upper end of the vertebral 
column, nearly balances itself. The importance of this 
arrangement is evident, because it enables us to keep the 
head erect with comparatively slight muscular effort. The 
contrary would have been the case had we been called 
upon to support a large and heavy muzzle. The elastic 
ligament present in other animals is thus rendered un- 
necessary. At the same time there is proof that some 
slight muscular effort is required to keep the head upright, 
for, if a drowsy person be watched, the forward nodding 
of the head is an indication that the muscles which support 
it are becoming relaxed. It may be noted that the position 
of the skull exerts an influence on the plane of vision in 
man : in the erect position the visual axis is directed 
towards the horizon, ' He looks the whole world in the 
face'; and the occasional remark that one has a 'hang- 
dog ' expression has more significance in it than at first 
appears. 

So lar we have dealt generally with the physical attributes 
of man. It is unnecessary here to dwell upon those higher 
mental and moral developments which distinguish him 
from the brutes. 






•^ 



IS 



i 



23 



MALE SKELETON, SIDE VIEW 



CHAPTER II 

GENERAL DESCRIPTION OP THE BONES AND JOINTS 

In the previous chapter great stress was laid on the 
iuiluence exerted by posture on the bodily framework ol 
man. The reader must now consider some points con- 
nected with the skeleton as a whole, before proceeding to 
study it in detail. Fortunately for the art student, a « 
minute description of all the bones is unnecessary, as many 
of them have little or no influence on the surface forms. 

The term ' skeleton ' is applied to the solid framework 
of the body. This consists largely of bone, but also includes 
cartilage or gristle, and ligaments. An examination of 
a skeleton as ordinarily prepared is somewhat misleading. 
In the process of maceration, to which for the purposes 
of preparation it is subjected, the cartilaginous and 
ligamentous elements of this framework have disappeared, 
being more easily disintegrated than the osseous parts. 
The result is that the dried bones convey but a poor 
impression of the delicacy and precision with which the 
several portiijiis of this skeletal framework are jointed 
together. 

It would appear at first sight almost hopeless to attempt 
to classify the bones of the body, but a closer examination 
will prove that there are many points of resemblance between 
them, not only in regard to structure, but also in regard 
to function. There are bones which are characterized by 
their length; these we find in the limbs, for example, the 
bones of the upper arm, ibre-arm, thigh, and leg. Such are 
clearly associatfid with movement, for their extremities 
are moulded into .snujolli ai'ticiiJar surfaces, Avhich fit more 



Classification of Bones 25 

or less accurately on the corresponding areas of adjiicent 
bones. Of the joints so formed each is specially adapted 
for particular movements. To these long bones the muscles 
are attached, which move them and convert them into 
levers of different kinds, examples of which will be 
easily recognized by the student of mechanics. This lever 
principle is not confined to the long bones. If one of 
the irregularly-shaped bones of which the vertebral column 
is built up be examined it will be seen to possess a number 
of prominent processes. Some of these afford attachment 
to muscles and act as ^levers, enabling these muscles to 
operate with greater mechanical advantage. In addition 
to the use of the long bones as levers, it must also be borne 
in mind that they act as supports. Having reference to 
what has been already stated in the previous chapter, we 
see that the bones of the lower limb are stouter and 
stronger than those of the upper; moreover, their articular 
surfaces are more expanded, and, if the range of movement 
of the joints which unite them be less, there is this 
advantage, that the articulations are stronger and better 
fitted to bear the strain to which they are subjected. 

Another group of bones are those which are more or 
less flattened and expanded — plate-like bones they are called. 
Generally speaking, these sei-ve as protective coverings 
for the more delicate structures which are lodged beneath 
them. On examining that part of the skull which contains 
the brain, it is seen that the oval case which envelops 
it is made up of a number of such expanded bones firmly 
united together. So also, in the pelvic region, the bones 
which constitute the girdle of the lower limb afford 
protection to the viscera which are lodged within its 
cavity. But nature takes advantage of these expanded 
surfaces in other ways ; besides protecting the organs which 
they overlie, they afford extensive surfaces for the attach- 
ment of muscles on their outer or exposed surfaces. Thus, 



26 Chest-wall 



in 



the head, the region of the temple, which in the skeleton 
is formed of expanded portions of the temporal, parietal, 
frontal, and sphenoid bones, affords attachment to one of the 
powerful muscles of mastication— the temporal muscle, which 
raises the lower jaw. It has been already noted how the 
outer surface of the pelvic girdle furnishes wide areas for 
the origin of the muscles which pass to the thigh-bone 
a ad control the movements of the hip-joint. 

In the examples above cited the protective bones are 
firmly united to each other, no perceptible movements 
taking place between them. In the animal economy it is, 
however, sometimes necessary to provide an arrangement 
which, whilst protective, will also be capable of certain 
movements : such, for instance, is the chest- wall. This 
consists of an osseous framework composed, on either side, 
of the curved ribs united in front with the breast-bone 
and connected behind with the vertebral column by a series 
of movable joints. This bony framework, combined with 
cartilage, membrane, and muscle, forms a highly elastic, 
movable, yet relatively strong protecting case for the heart 
and lungs which are placed within its cavity. Movement 
in this instance is required in order to provide for the 
bellows-like action which is necessary to draw in and expel 
the air i'rom the lungs. Here again, advantage is taken 
of the extensive outer surface of the chest-wall to provide 
attachment for the numerous muscles which pass from the 
trunk to the upper limb, another example of the economy 
of space and material practised by nature. 

The remaining bones may be classed as those of irregular 
shape : such are the bones of the face, which are very com- 
plicated in their structure. These are admirably adapted 
fur the protection of the various delicate organs of special 
sense which are lodged in this region, while at the same 
time tliey aflbnj attachment to the muscles of expression. 
Further, the bones which form the vertebral column are 



Joints 27 

of irregular shape. When articulated together, they afford 
complete protection for the delicate nervous centre, the 
spinal cord, which lies within the osseous canal formed by 
their neural arches, whilst their outstanding processes 
not only furnish attachments to the muscles which directly 
control' their movements, but also provide points of origin 
for many other muscles which act upon the limbs and 
head and neck. Again, the small bones of the hand and 
foot are examples of irregularly-shaped bones ; they will 
be considered when these members are described. 

As has been stated, the appearance of the dried skeleton 
conveys little idea of its perfection in the living body. 
The bones have been denuded of the soft parts which 
bind them together and form the joints. It is necessary 
therefore to say something generally regarding these 
articulations. 

If the bones entering into the formation of the hip-joint 
be examined, it will be noticed that the rounded head 
of the thigh-bone fits loosely into the cup-shaped cavity 
of the haunch-bone ; but, if a recent specimen be inspected, 
these articular surfaces are seen to be covered by a 
layer of smooth gristle or cartilage. If these cartilage- 
covered surfaces be placed in contact with one another 
they will be found to fit with remarkable accuracy. 
Moreover, the opposed surfaces are so smooth that the 
bones can be moved on each other with the least possible 
amount of friction. So accurate, indeed, is the fit of 
these articular surfaces that it is possible, in some instances, 
to keep them in contact by the influence of atmospheric 
pressure alone. 

But some arrangement is necessary whereby the op- 
posed surfaces may be held together. This is provided 
for by structures called ligaments. These ligaments are 
bands of fibrous tissue which completely surround the 
joint forming its capsule. The thickness of this capsule 



28 



Movable Joints 




varies on different aspects of the joint ; and in some situa- 
tions the thickening of the capsule forms specialized 
bands which are described and named as separate liga- 
ments. At other points the capsule is so thin as merely to 
consist of the layer to be next described. This is a delicate 
membrane which lines the interior of the capsule, called the 
aynovial membrane. It secretes an oily fluid called synovia, 
which hibricates the articular surfaces of the joint and so 

reduces friction to a minimum. Such 
is the structure of a movable joint : its 
strength depends on the form of its 
articular surfaces and the stoutness ot 
its ligaments ; but, whilst these liga- 
ments are useful in binding together 
the joint, they also, in many instances, 
limit or check its movements, especi- 
ally when such an effect is not pro- 
duced by the locking of the bones 
themselves. 

The accompanying figure may assist 
in explaining the details above de- 
scribed. 

But there are other varieties of 
movable joints : the type mentioned 
above possesses a joint cavity, and a 
wide range of movement. The next 
class includes those joints in which 
tluTo is no joint cavity, and in which the movement is 
limited iu its extent. If a fresh vertebral column be 
examined, the bodies or solid parts of the vertebrae are 
seen to b; united by means of pads of laminated fibrous 
tissue jiud pulp matter, which bind them together and 
jxTiiiit only a limited movement between any two segments. 
The movement between the individual bones is small, but 
if the nmiibor of such segments be taken into account the 



Fig. 15. Diagram- 
matic section through 
a movable joint. 

a. The thick black lines 

represent the carti- 
lage-c<ivered articu- 
lar surfaces. 

b. 'V\m joint cavity. 

c. The lii^aiuc-nts around 

foruiinj; the capsule, 
the interior of wliic^li 
is lined by synovial 
membrane represent- 
ed by dotted linos. 



Immovable Joints 



29 




amount of movement possible in the column as a whole 
is very considerable. The arrangement may be better 
understood if we compare the back-bone to a number 
of wooden disks cemented together by pads of india- 
rubber j the movement between any two disks will be slight ; 
but, suppos-ing we have a chain of such disks similarly 
united, the column so formed will acquire a remarkable 
flexibility. As will be seen hereafter, these intervertebral 
disks, as they are called, not only allow of movement, but 
also serve the useful purpose of acting 
as buffers to reduce the shocks which 
are from time to time transmitted along 
the chain of bones which they unite. 

Fig. 16 represents the general ap- 
pearance of such a joint. 

There are other kinds of joints in 
which there is no movement. These 
may be compared to the dove-tailed 
joints employed in carpentry; they are 
of little importance from our stand- 
point, as we are only concerned with 
the forms produced by their union. A 
word or two is, however, necessary in 
regard to these particular forms of 
joints, because without a knowledge of 
their structure it would be impossible to account for the 
growth of certain parts of the body. The most typical 
examples are met with in the skull. The several bones 
which cover in and protect the brain are seen to be united 
at their borders by a series of interlocking teeth. If we 
examine a fresh specimen, or, better still, the skull of an 
infant, it will be observed that there is a layer of membrane 
between the opposed borders of the bones ; so long as this 
membrane persists growth may take place, but on its disap- 
pearance osseous union occurs between the contiguous bones. 



Fig. 16. Section 
through a joint pos- 
sessing no joint cavity. 

a a. The bodies of two 
vertebrae united 

by 
6. The intervertebral 
disk, the central 
part of which is 
softer and more 
pulpy than the 
circumference. 



30 



Immovable Joints 



In this way it is possible to understand how increase in size 
takes place, and how the bony walls of the cranial box 
expand to allow the growth of the brain. When growth is 
complete the necessity for this expansion no longer exists ; 




Fig. 17. Shows tlie arrangement by which the bones of the top 
of the skull are united by serrated joints called sutures. 

and if the skulls of old people be examined it will not 
unfrequently be found that all trace of these joints, or 
ffufures as they are called, has disappeared, the bones having 
become ossified together. 



CHAPTER III 



VERTEBRAL COLUMN OE SPINE 



It will now be necessary to take up in detail the con- 
sideration of the various parts of the body. 

For descriptive purposes it is no doubt convenient to 
furnish a separate account of the bones, joints, and muscles, 
and such a method possesses great advantages in the 
study of scientific anatomy ; but a knowledge of much 
of the detail which it is necessary the medical student 
should possess is altogether useless to the student of art. 
The bones, joints, and muscles all form part of one great 
system, and it will, it is hoped, serve our purpose better 
to consider them together as the various regions of the 
body are studied. 

Although the divisions of the body suggested in Chapter I 
are not, strictly speaking, scientific, yet they are convenient, 
and for the purpose in view may be adopted with advantage. 

Commencing with the description of the trunk, it will 
be necessary to examine the central axis or vertebral 
column, the chest- wall, and the pelvis ; though, as we have 
seen, the pelvis is, properly speaking, the girdle of the lower 
limbs. The trunk corresponds pretty closely with what, in 
artistic language, is called the torso, with this difference, 
that the latter includes portions of the upper and lower 
limbs. 

An examination of the back of the trunk involves a more 
detailed description of the vertebral column than has 
hitherto been given. The back-bone, represented in 
the accompanying figures, is seen to consist of thirty-four 
bones placed one on the top of another. This statement, 



32 Vertebral Column 

however, requires some qualification, for, if the skeleton bo 







"SZ 



a 



m- 



m 



Fig. 20. Back view. 



Vcrtcbual column. 

Fig. 19. Sid(^ view, 

showing curves. 

a. Corviral vrrtchrnc, aovon in number. d. Sacrum, formed by fusion of five 
6. Domiil or tbcracir, voriobrac, twclvo seRnionts. 

in nnml)or. r. Coccyx, made up of four or five seg- 
e. Lumbar vfrtidirao, five in miinlicr. monts. 



moro carofully nxaminod, flic lowcir ten of these sep;ments 



Vertebrae 33 

are seen to have become fused together in the process of 
growth to form two separate bones each consisting of five 
segments : these two bones are not unfrequently more 
or less united. They are the sacrum, to which reference 
has been already made, and the coccyx, which is formed 
of the dwarfed tail vertebrae of man. 

The remaining twenty-four vertebrae are separate and 
distinct, so that we have an easy means of subdividing 
the column into (a) the region in which the vertebrae, 
twenty-four in number, are movable, and (&) the part com- 
prising the sacral and coccygeal portions of the column, 
formed by the fusion of ten segments, in which the 
vertebrae are immovable. 

Proceeding with the examination of one of the movable 
vertebrae, it is seen to consist of a solid part in front, more 
or less disk-shaped, which varies in size and thickness ac- 
cording to the part of the column from which the specimen 
has been taken. Fused on to the posterior aspect of this 
solid portion or body, there is an osseous arch which thus 
includes between it and the body a more or less circular 
hole. Connected with this arch are a number of pro- 
cesses, some of which are articular and assist in the 
union of the various vertebrae together ; others are long 
and outstanding, and form levers to which muscles are 
attached. Of the latter, one springs from either side 
of the arch and forms the transverse process, the third 
or remaining one juts out from the centre of the arch 
behind and is known as the spinous process. The length 
and direction of these spines vary in different regions 
of the vertebral column, and, as will be presently shown, 
have an important influence on the surface contours of 
the back. If two or three of these vertebrae be taken 
from the same region, and placed one on the top of the 
other, it will be seen that the bodies or solid parts rest on 
each other, whilst the arches form an interrupted osseous 



7 External oblique, 

8 Brachialis anticus. 

9 Lumbar aponeurosis. 

10 Internal condyle oj humerus. 

1 1 Bicipital fascia. 

12 Iliac crest. 

13 Posterior superior iliac spine. 



Trapezius 



Tendinous area of Trapezius. - 

Trapezius^ ^ ^ 
Spine of scapula. 

Deltoid.^ 

Infra-spin^ ^ ^ 

Rhomb. 7naj^ 

Teres. maf^ 




11 

7 

12 

13 — --' 

Gluteus mcdius 
Tensor fasciae fcntr. - 

Trochanter major. - 
Gluteus maximus.- - 
Ilw-tibial band. 

Adductor /naj^us.. ^ui 

Semimembranosus. _ 
.Semi-tendtnoius. - 

Biceps cruris. 

Vastus cxttrnus. - - 



Triceps, long head. 1 
Triceps, outer head. 2 
Latissimus dorsi. 3 
Biceps cubiti. 4 
Triceps tendon. 5 
Triceps, inl.head. 6 

_ _ Trapeziuii 

Spine of VII cervtca 
vertebra. 

Acromion process 
Spine of scapula 

^ Deltoid. 

Infraspinatus 
Jihomb. maj 

Teres may 

,^' 1 

^ \ ' 2 

^'^^,- 4 

.-' 5 

6 

7 

.-'- 8 

Inter, 
'condyle 
--Olecran, 

Bicip.fasc. 

Flexor mass. 

Gluteus mcdius. 

Tensor fasciae fem 

Trochantey tnajor. 

I 

Gluteus ttiaximus 

~ ~Ilio-tibial band 

Gracilis, 
— Semi-menibranosus. 

Senii-tendifiosus, 
— Vastus cxternus. 



Vertebrae 



35 



canal which contains a,nd protects the spinal cord. At the 
same time the muscular processes fall in line, the spines 
forming a series of projections in the middle, the lateral or 
transverse processes being arranged in a similar series of 
projections on either side. The lateral rows of projections are 
separated by a groove from the mesially-placed row of spines. 
This groove varies in width and depth in different parts of 
the column, and is of great importance, as herein are placed 



.r. e 





Fig. 21. View of a dorsal 
vertebra as seen from above. 



a. Body or centrum. 
h. Transverse process. 

c. Spinous process. 

d. Articular surface on transverse pro- 

cess for tubercle of rib. 

e. Articular processes by means of which 

adjacent vertebrae are jointed to- 
gether. 



Fig. 22. View of two dorsal 
vertebrae articulated together 
as seen from the side. 

/. Articular facets for head of rib. 
q. Neural arch, in which the spinal cord 
is lodged. 
In Fig. 22 the space between the bodies 
a a of the two vertebrae is, in the recent 
condition, occupied by an intervertebral 
disk. 



the erectores spinae muscles, of which mention has been 
already made as helping to hold the column upright. 

Thus the column consists of a series of solid parts in 
front, an intermediate series of arches which enclose a canal, 
and three more or less distinct rows of processes at the sides 
and behind ; but, as has been stated in Chapter II, the 
bodies of the vertebrae are united by fibrous disks, so that 
in this way a column is formed possessing stability combined 
with flexibility. If we consider the functions this part of 
the column is called upon to discharge, we find (first) 
that it supports not only the framework of the chest-wall 

D 2 



•;6 Vertebral CoUirnn 



o 



and, through it, the upper limbs, but also carries the head 
on its upper extremity. In addition to upholding the 
weight of these 'structures, it has also (secondly) to reduce 
the effect of any shocks to which it maj^ be subjected. 
Every step we take is accompanied by a jar which, if not 
reduced in intensity, would render such acts as leaping 
and running an impossibility ; for, if there were not some 
such arrangement, the shocks would be transmitted direct 
to the head and give rise to disturbance and injury of the 
delicate nervous centres lodged therein. As has been 
already explained, the reduction of the shock is largely 
due to the buffer-like action of the intervertebral disks. 
As will be seen, however, from an inspection of the 
articulated skeleton, the vertebrae are not placed one on 
the top of the other in a straight line, but are arranged 
in a series of curves which, acting after the manner of 
bent springs, likewise tend to reduce the transmission 
of these shocks. Before describing the character of these 
curves, it is necessary first to subdivide the movable 
vertebrae according to the regions in whicli they are 
placed. The twenty-lour movable vertebrae are thus 
apportioned : seven are found in the neck, and are hence 
called the cervical vertebrae; twelve enter into the for- 
mation of the cliost or thoracic wall, and are known by 
the name of th<; fJwracic or dorsal vertebrae ; the remain- 
ing five arc situated in the region of the loins, and are 
termed himhar vertebrae. The results can now be tabulated 
as follows : — 

VeIITEI311AE. 

34 
Movable = 24 Iinniovable = 10 



Cervical Dorsal Lumbar Sacral Coccygeal 

7 '2 5 55 

There are four curves in llir', column -a forward curve 
111 the cervifal region, a backward in iho dorsal region, 
a forward in Ih.' lumbar n-'ric^n, and a backward in the 



Curves of the Column 37 

sacral region. Of these four curves, as has been already 
stated, two only exist at birth, viz. those associated with 
the formation of the thoracic and pelvic cavities ; these 
are the primary curves, and are both directed backward. 
The secondary curves are those in the cervical and lumbar 
regions ; they are forward curves, and, as has been explained 
in Chapter I, they only attain their full development after 
the assumption of the erect posture. As will be seen by 
a reference to Fig. 20, these curves pass imperceptibly into 
one another, with the exception of the lumbar and sacral 
curves ; in these the transition from the forward to the back- 
ward curve is sudden and abrupt, and forms the projection 
known to anatomists as the sacro-vertebral angle — the bony 
promontory which overhangs the cavity of the pelvis. 

The curves formed by the bodies of the vertebrae are, to 
a certain extent, repeated by the line connecting the tips 
of the spinous processes. The latter have a very important 
relation to the surface contours of the back, for, if the fingers 
be carried firmly down the middle line of the back from 
the lower part of the neck to the inferior extremity of the 
column, the tips of these processes can be distinctly felt and 
in some positions seen (PL, p. 50). It is well to examine them 
carefully in the skeleton to see how far they accurately repeat 
the curves of the anterior outline of the column. As has been 
said, the length of these spinous processes varies in different 
situations; not only so, but their direction alters considerably; 
in some cases they are directed almost horizontally back- 
wards, in other instances they are very obliquely placed (see 
Fig. 20). These facts have a very important influence in 
modifying the contour which is formed by the line con- 
necting their tips, and we find that, whilst they repeat 
generally the curves of the solid part of the column, they 
are neither so prominent nor so well marked ; thus in the 
neck the spines of the cervical vertebrae are short, with 
the exception of the second and last, and the curve formed 



38 



Trt f ni tu. 



Im/rtifniia. 




Tmpt.lmtlimJ. ,'' 
Tmfi trmdm..,_ 
Biafjrwtiti..J" 

BrtdmHi tm/btm': 

/mtirmtJ rmjfk. 

BmfUtl /mtcm^ 

Z^Ai/rarai Jtm.. 

Prtm^ftw r^ii ttm 

Ptlmarit tamgut 

tkx^ ,arf, mimtru. 

ExItrmtJithfme 
Lmmimr t f mt tv iiw . 

/liaiCTtll..j..fy 

TrtcJumUr mt/tr. -S.J^JJ. ..j^l^ 

Tmttr Jtxmi ftm - JP ^ 

GbUm m*i\tat. 

CntUii. 

AMmt$ir tmpnu. 

Srmt -// Wffwff , 

Butf$ ermhs^ 

I'stlui attrmmj. 



_ ,5/wK e/ Vil an. verl 

^.Trapezius. 
. Acrmmn pnctss. 
•'' Jiellmd. 

■■' yExtmscrs of thumh. 
'•' , Bleep i nhiti. 
■•' ^.Ext.carfi ratLbrivior., 
• ■' ^,Siipinator hngus. 
■ ■' ^Brachialis anticus. 
- ' ,hxt. com.digitorum. 
^^^\\\Y^\^^ ''^•'''^N. Vf^vW ••■' JExl.carpirad.lmgioT. 

Trictfs, outer /leaJ. 
^Aneoneus. 
. . External condyle. 
. Olecranon proc. of ulna. 
-Triceps tendon. 

Trteeps. iong head. 

Teres major, 

,Jnfra.spinatus. 

Rhomhoidf us major, 

^Latissimus dorsi. 

Mxternat oblifue. 

Lumbar aponeurosis. 

-- External ohtigue. 

— lUac crest. 

Post. sup. iliac spine. 

Gluteus medtus. 

Gluteus maximus. 

Trochanter major. 

_ Tensor fasciae fcmoris^ 

Rectus femoris. 



Slermo-mtiUu/ 

Tr.,p.:,., . 
//•V*» <<» 1/ O </. 
•nf... ^/ lUr ^mail ■■ 

i'eilfVtor lr%emgU 
(•/.!•../, 

DtllmJ 

fi'-it km, Ulenmm) . 

A mmmlmr i,g ,f nrrul. .._ 

Slf4md pnt-o/ ulmt . 
f.tlurf, u/ma,,!^' 

f itM^e 4drft ulnsrtt 

ttrtemtntt^t. 

Ptlmmrt, Lmi*. 

hlttm imrp. ,a^,„„ 

Amomm 










. Furrow between pect 

Fiwroui 6twn. st. ^ c^ 
parts of ptct ma/. 
..Peelora/ts ni.ijor, 

sttrnal Jbrcs, 

• "' Latissimus tfoni. 
...THceps, out€r had. 

..Biceps tubiti. 
.. Brackiaiis anticus, 
^,. Triceps temUn. 

. .Serratm magnus. 
.. -Supinator lon^s. 
....Anconeus. 

Extensor carpi rad.iong, 
-• E.xternal oblique. 

Extensor airp, ulnans. 

■ extensor rommunts dig. 

■ Extensor carpi radbrev. 

• Extensors o/ thumb 

• ■ Rectus abdominis. 
An/juperior i/iat sPine. 

■ I ensor fasciae femoris. h 
.J^ouparfs lieamenl. ^H 
.lUopsoas ■'< 

Rectus femoris. _^^U 

Sartonus. ^H| 

Pectoteiis. ^H 

. Adductor tonguS' ^^"1 

.'Cra(i/is. 

yuitas iiiternui. 





V ^V 



^ 





Curves of Back 39 

by a line passing through their tips is irregular and does 
not correspond accurately to that on the front of the 
column in this region ; but the posterior curve is of little 
importance in relation to the surface contour of the back 
of the neck, as the short spines lie imbedded in the 
fleshy muscles of the back of the neck at some considerable 
depth from the surface, a fact which can easily be verified 
by the difficulty one experiences in feeling them. The 
spine of the last (seventh) cervical vertebra forms a striking 
exception to this arrangement. Owing to the unusual 
length of the spine of this vertebra it has been called 
the vertebra i^^ominens. Its projection on the surface of 
the back just at the junction of the neck with the upper 
dorsal region forms a very characteristic landmark (see Pis., 
pp. 34, 94, 104, 138). Below this point the curve of the middle 
line of the back depends on the projection of the spines of 
the thoracic vertebrae, but, owing to the varying length and 
altered degrees of obliquity of these processes, the curve so 
produced is flatter and less pronounced than the curve formed 
by the anterior outline of the column in this region. In like 
manner the curve formed by the spines in the region of the 
loins is shallower than that displayed on the anterior surface 
of the column in the corresponding situation, and there is 
no sudden interruption in the flow of the curve from the 
lumbar to the sacral region such as we have seen exists an- 
teriorly. The backward thrust of the sacrum is diminished 
owing to the fact that the thickness of the bone is rapidly 
reduced, a circumstance which naturally reacts on the 
prominence of its curvature. 

As will be seen, therefore, the contour of the middle 
line of the back, whilst repeating to a certain extent 
the outline of the front of the column, yet displays 
considerable modifications, particularly in the direction of 
exhibiting these curves to a less marked degree. These 
details are evident in Fig. 23. 



40 



Grooves for Muscles 



Fio. 2'). Diagram to sliow fli:it 
the curves loriiicd hy tho lino 
connecting the tips of the spinous 
|>ro<;(fH8«'H do not correspond to 
the curveg j)ri)duced hy tlio an- 
terior outline ot the column. 

The Ktron(f hlack lino corro- 
BlKjnilH to t he contour of the l>a(;k 
in tlio middle lino ; the dotted 
line repreHentii the profile outline 
of the hiw.k, which diHorB troni 
the foregoing, owinjf to the thick- 
nitwiof the flenhy muscdoB around 
I he •houider-hlade above, and the 
development o( tiie niuH*Ie« of 
the hutto<k below. 



The grooves which lie on either 
side of the central ridge of spines 
require further notice, particularly 
if a skeleton be examined in which 
the ribs and pelvic bones are arti- 
culated with the vertebral column. 
The two haunch-bones are seen 
to be united to either side of the 
sacrum, and their upper and back 
parts project considerably behind 
the surfaces of their attachment 
to that bone ; the result is that 
they limit externally these lateral 
grooves as they run down the back 
of the sacrum. In this . way the 
groove in this region on each side 
is much deepened, and an exten- 
sive surface for the attachment of 
muscles thus formed. 

On tracing the groove upwards, 
into the mid-dorsal region, it is 
found to become very shallow from 
the fact that the spines are not so 
prominent; owing to the arti- 
culation of the ribs with the 
vertebrae, however, the groove 
though shallow is much wider, for 
the shafts of the ribs, as far as 
their angles (the points at which 
they bend forward), assist in form- 
ing its floor. Above the mid- 
dorsal point it again deepens. 

Lying in this groove, on either 
side of the median spines, is the 
great flesliy column of the erector 



Erector spinae 



41 



spinae muscle, which takes origin from the posterior surface 
and spines of the sacrum, 
the spines of the lumbar, and 
some of the lower dorsal 
vertebrae, and in addition 
receives fibres of origin from 
the posterior border of the 
haunch-bone, and from the 
posterior superior iliac (or 
haunch) spine^, as well as 
from the upper border of 
that bone in its posterior 
fourth. This muscle, which 
is very complicated in the 
arrangement of its fibres, 
breaks up into a number of 
subsidiary muscles, which 
have been separately de- 
scribed and named by ana- 
tomists : from our point of 
view, however, it may be 

^ The posterior superior iliac 
spine is the name given to the 
prominent posterior extremity of 
the upper border of the haunch- 
bone. 



a. Placed over tendinous part of erector 

spinae. 

b. Posterior superior iliac spine. 

c. Haunch-bone (os innominatum). 

d. Socket (acetabulum) for head of thigh- 

bone. 

e. Tuberosity of the ischium. 

f. Placed over fleshy part of erector 

spinae. 
(J. Splenius muscle. 
h. Mastoid process of temporal bone. 
i. Complexus muscle and superior curved 

line of occipital bone. 




Fig. 24. Shows the great erector 
spinae mass of muscles. The muscles 
are shown only on one side, the 
groove in which thiy are lodged is 
seen on the right side of the tiguie. 



42 



Erector spinae 



regarded as one muscle having many attachments, being 
reinforced by additional slips as it ascends, and at the same 
time furnishing tendons of insertion to the ribs and trans- 
verse processes. As the groove in which 
it lies becomes shallower in the dorsal^ 
region, the muscle spreads out and 
thins, to become again more fleshy and 
more powerfully developed as it is con- 
tinued into the upper dorsal region and 
the back of the neck as far as the base 
of the skull, to which it is ultimately 
attached. The fleshy mass at the back 
of the neck is further increased by the 
addition of muscles which need not 
here be particularized ; these are im- 
mediately concerned with the move- 
ments of the head and neck. 

A glance at the accompanying dia- 
gram will enable the reader to recognize 
that the lower part of this muscular 
column is particularly concerned with 
the control of the movements of the 
lower two-thirds of the back-bone, 
whilst the upper part is more imme- 
diately associated with the movements 
of the head on the column, as well as 




Lirram 



P'k;. 25. a dia 
to show the arrange- 
ment of the muscles 
which 8iij)port the 



backbone. The mus- 
cles, which are repre- those of the upper part of the column 
sented in solid black, itself, 
are seen to be thick 
in the regions of the 
loins and neck, and 
conij aratively thin in 
the niiddoreal region. 



Whilst the erector spinae has a free 
admixture of tendinous fibres through- 
out its entire length, these form a dense 
ayer on the superficial aspect of the 
attachment, and this requires special 
attention. It extends as liigh as the second lumbar spine, 
close to the uiiddlo line, and, further, passes up as a pointed 



111 use lo at its lower 



Erector spinae 43 

process over the middle of the fleshy column, as far as the 
mid-dorsal region. The outer margin of this tendinous 
area describes a curve of varying outline, which terminates 
below at the posterior superior iliac spine. (See Fig. 24.) 

This arrangement of the fleshy and tendinous fibres of 
the muscle, in a well-developed figure, affects the surface 
contours, the fleshy fibres of the muscle forming, during 
powerful contraction, a more distinct elevation than the 
tendinous portion (Pis., pp. 44, 50). Whilst this fleshy mass 
is not, strictly speaking, superficial, the muscles which over- 
lie it, particularly at the lower part of the back, consist 
merely of thin tendinous layers ; at a higher level, though 
fleshy, they are sheet-like muscles, and their thickness, if con- 
siderable, is not sufficient to entirely obliterate the rounded 
form which the underlying muscular column imparts to 
the surface. It is on account of the development of these 
erectores spinae that the middle line of the back is con- 
verted into a furrow, the muscles bulging up on either side 
(Pis., pp. 34, 36). This is particularly noticeable when these 
muscles are in a powerful state of contraction, as when a 
person is supporting a heavy weight on the head or shoulders, 
or is bending backwards (Pis., pp. 38, 44, 52, 98, 138, 182). 
If, on the other hand, we examine the back of a model when 
the figure is bent forwards, we notice that the median groove 
to a large extent disappears, and, in many cases, the spines of 
the vertebrae may be observed forming a prominent ridge 

(PI., p. 5°)- 

It will thus be observed how misleading the appearance 
of the skeleton is, for it by no means follows that because 
a prominent process of bone is near the surface its position 
is indicated by a surface projection. In fact, as we shall 
see hereafter, such bony ridges or projections frequently 
correspond to furrows or depressions on the surface of the 
body. The depth of the median furrow of the back will 
therefore depend largely on the development of these 



44 



t»m£Ui. 



Bictfs. 




BUtft. 

Truest, 
iifirr Htftd. 

' ^' .. . 
■ 'lull, I 

•41111,111. 

OUtranon 

tnUrnal 

tonitylt. 



TJ HI Urn. 

fiuifil.ll 

/»I<|>1. 

Palmar II 



fell tup. 

ilim> ifiut 

Iwuior/.ii 

Jimorii 



Erector spinae 45 

muscles, their state of contraction, and the posture of the 
body. We have only to examine the back of a weakly 
person and compare it with that of an athlete to see 
at once the extent to which these muscles influence tho 
surface contours. 

On tracing the median groove downward, we find that 
it not unfrequently ends in a depression or dimple, which 
usually corresponds to the position of the second sacral 
spine ; below this point the furrow fades insensibly into the 
cleft between the buttocks. The groove itself is best marked 
in the region of the loins, in which situation there are often 
indications of the presence of the lumbar spines, as demon- 
strated by the unevenness of the bottom of the furrow ; it 
becomes shallower again above, where it is interrupted by 
the outline of some of the more superficial muscles (Pis., 
pp. 34, 52, 182). 

The lower attachment of the erector spinae is associated 
with two distinct depressions on either side ; one corresponds 
to the outer border of the attachment of its fleshy fibres to 
the posterior fourth, or so, of the iliac crest (Pis., pp. 34, 44, 
52, 94). As Richer has pointed out, this is only seen in men ; 
in women the more abundant deposition of fat in this region 
obliterates this little hollow (Pis., pp. 36,52, 142, 278). The 
other depression corresponds to the position of the posterior 
superior iliac spine, from which the tendinous fibres of tho 
muscle spring, and this little dimple is common alike to male 
and female. These two latter depressions combined with the 
furrows on either side, corresponding to the posterior border 
of the haunch-bones and the outer converging margins of tho 
sacrum, mark oif a somewhat depressed triangular area, over- 
lying in part the posterior surface of the sacrum. It is this 
area which is, as it were, wedged in between the prominences 
formed at either side and below by the projection of the 
buttocks. It should be noted that the angles of this triangle 
are all fixed points, and, whatever be the relation of the 



46 



Erector spinae 



surrounding parts as influenced by change of posture, the 
limits of this area remain always the same (Pis., pp. 34, 
52, 94. 98). 

In the lumbar region, in the male the outer margin 




Fig. 26. 



of fho oreotor mass is iiulicatnd by a shallow depression, 
whicli separates it from the flank (Pis., pp. 34, 38, 44, 50, 
94, 98, 162). 

The movements of the cohuiin are exceedingly complicated. 



Movements of Column 47 

In attempting to analyse them, the student should bear in 
mind the facts already stated, viz. that the column consists 
of a part made up of separate segments, and a part in which 
the originally separate segments have become fused together 
in the process of growth. The latter comprises the sacrum 
and coccyx, the former includes the parts of the column which 
lie in the neck, thorax, and loins. Movement can alone take 
place in those parts of the column in which the vertebrae 
are separate. Further, it is well to note, for reasons already 
explained, that the sacrum is firmly and immovably con- 
nected with the haunch-bones, to form the pelvis. In this 
way a fixed base is provided for the upper and movable 
part of the 'back -bone ', and any movement of the pelvis 
as a whole, either at the hip-joints or by rotation on the 
thighs, necessarily involves an alteration in the position 
of the base on which the movable part of the column rests. 

As has been shown, the upper or movable part of the 
vertebral axis displays certain curves : a forward curve in 
the lumbar region, a backward in the thoracic region, and 
a forward in the cervical region. 

These curves are necessarily much modified, though not 
to the extent we might imagine, when the back is bent 
forwards and backwards ; these movements are termed 
flexion and extension respectively and are freest in the 
lumbar and cervical regions. They are not so free in 
the thoracic region, for here the cage-like structure of 
the chest-wall limits the range of these movements. The 
power of bending forward in this part of the column is 
checked by the compression of the thoracic wall, whilst 
the extent of the backward movement in this region is 
limited by the resistance of the chest-wall to further expan- 
sion ; again, the overlapping of the spines of the dorsal 
vertebrae mechanically checks extension of the column in 
this situation. 

Flexion is freest in the loins, extension in the neck. As 



48 



Movements of Column 



has been already pointed out, the spines' of the cervical ^' 
vertebrae are short, hence they do not interfere with the 
movement of extension, as is the case with the spines of 
the dorsal vertebrae. 

In throwing back the head and trunk, the curve described 
is not a uniform one, on account of the limited range of 
extension in the dorsal region, as shown in Figs. 26, 27. 




Fio. 28. 



It is to 1)0 noted that when the body is bent forward the 
hollow in ili(; lumbar region disappears, and for it is sub- 
stituted a curve, which blonds above with thatof the thorax, 
thus leading to a more flowing and uniform outline. 

It will be ol>sorved, however (Fig. 23), that the outline 
of tlio figiin- ill exact profile does not correspond to the 
curve of the median lino of the back, from the fact that 



Movements of Column 



49 



the muscular projections on either side of the column, 
particularly in the region of the shoulder-blades, conceal 
from view the middle line of the. figure. 

Lateral movements of the column are also possible, the 
trunk being bent to one or other side. This movement 
is freest in the neck, extremely limited in the lumbar 
region, and not great in the thoracic region, for here it 




Fig. 29. 

is necessarily associated with a compression of the chest- 
wall on the side towards which the body is bent, and an 
extension or stretching of the same structure on the opposite 
side. The range of this side-to-side movement is greatly 
increased by altering the position of the pelvis. The 
alteration in the position of the pelvis shifts the plane 
of the base (sacrum) upon which the movable part of the 



THOMSON 



E 



5^ 




Movements of Column 



51 



column rests. The movement of the pelvis is effected bj' 
the straightening of the leg on the side from which the 
body is bent, and the bending of the leg on the side 
towards which the trunk is inclined. This causes one 
side of the pelvis to fall lower than the other, and thus 
alters the position of the base of the column (sacrum) from 
a horizontal to an oblique plane. 

Further, when the movable parts of the column are bent 
from side to side, there is a slight rotation of the individual 




^}^C 





Fig. ^o. 



Fig. 31. 



Figs. 30, 31 show how the lateral inclination of the body is 
increased by shifting the pelvis from a horizontal to an oblique 
position. 



vertebrae, which causes their spines to be turned away from 
the side towards which the body is bent. This explains 
why the surface furrowsproduced do not correspond precisely 
to the middle line of the bent column (PL, p. 44). 

Whilst speaking of these lateral curves of the column, 
it is well to note the existence of a slight degree of lateral 
curvature which is sometimes seen in the backs of persons 
standing upright. This curve when present is found in the 
dorsal region, and has its convexity directed towards the 



E 2 



Teres tiin/'or. Infra s/>iinit lis. Dtlloul.^ Sfiiic o/ si)i/>ii/<t. Tru/iczitis. Spine of V 1 1 cervical vertebra. 



Rliomboiiieiis major. ^ 
Tricrps, loii^ luad .. 
TricffiK UiiHcut. „ 
Triceps, tuner licad. 

Biect>\ eiihili. 

Internal condyle. 

Olecranon process: '" 
Bicipital fascia 
Tliorneie wall. ... 
Poliuaris longiis. 

Flex. carp. rad.-- 
Flex. carp, iiln-.- ■•■■ 
Tat.dorst.-- 

Ext.otdiijue 
Iliac erest.- 

Post, ^up. Iliac 

spine. 

(j In tens incdiiis.-' 
Trochanter major. 
Tensor fasciae femoris 
Qluteus maximus 

Ilio-tibial band. 
/Idductor ma gnus 
Gracilis. 




Seiniteiidinosus. 

Bicrpy cruris. 

Vastus ex tern us.- 

Seniimcnibranosus."---:::::: 

Snrloriu 

popliteal space 

CtistrcKHcniiiis, outer head 
Casfrociuiiiim, inner head 

Soleu\. 



I'croueiis h>ngut 
Solent. 



' -Spine of . pit la. 
■ ." I*i/ra-spiuatus. 

""—'■. Deltoid. 
Rtminboideus major. 

"■"•-.. Teres major. 

'" ■ Latissimiis dorsi. 

- Triceps, long head. 

■Triceps, outer head 

Triceps, inner head. 

Supinator loitgns. 

Ext. carp, rad .long. 

Anconeus. 

Oleeraiion process 

Ext. com. dig. 

Extensor carpi nlnaris 

Bicipital fascia. 

Posterior border of ulna. 

Flexor carpi nlnaris. 

Palmar is longiis. 

Flexor carpi radialis 

\f Styloid process of ulna. 

Cracilis. 

Ilio-libial baud 

Sent I ■ ten din as us 

Vastus exteriiiis 

Biceps cruris. 

""Semi-membranosus 
Sartor ins 



Gastrocnemius, outer head 
Castrocnemiiis, inner head 



■ Solens 



Peroneus lougu. 
— Solcm 



Peroueui liretds. i 

Long flexor of great toe 

Internal malleidns. 

h xternal malleolus. 
Teiida /ichillii. 



Peroneus brevi 

Ten do A chilli 
External maiieolu 



I 



Movements of Column 



53 



/i) 



d 



I 



right side. It is probably due to the greater use of the 
right arm as compared with the left, and is associated 
with a more pronounced development of the muscles of 
the right upper limb. ^ 

Below this curve there is often a slight 
compensatory curve in the opposite direc- \ 
tion, which imparts a sinuous aspect to \ 
the back and relieves it of its appearance 
of stiffness. 

Movements of rotation may take place 
in the cervical and also slightly in the 
dorsal region. As we have seen, these 
movements are combined with the lateral 
flexion in the side-to-side movements. 
The power which we possess of turning 
the head round, so as to cast the eyes in 
a direction opposite to that in which the 
toes point, is mainly due to the existence 
of a special joint between the top of the 
column and the base of the skull, com- 
bined with the rotation of the pelvis (which 
supports the base of the column), on the 
upper extremities of the thigh-bones. This 
can be demonstrated in the following way. 
Standing erect, fix the pelvis by placing 
the hands on the haunches, turn the head 
to one or other side, without causing any 
perceptible. movement of the column, then 

rotate the column, still keeping the pelvis ^, ^ 

. ^ Fig. 32. 

fixed: if these directions be followed, it 

will be found that the eyes can be directed across the point 

of the shoulder. If now the pelvis be released, the further 

movement in a backward direction will be seen to be effected 

by the rotation of the pelvis on the thigh-bones, the one hip 

being advanced, whilst the other is directed backwards. 




54 



Trapezius. 



Tendinous area of Trapezius 
A croynion proc. of scapula. - - - . 

Deltoid.-- 
Rhomboideus mafoi 
Infra-spinatiiS. - - 

Teres major. 
Triceps, outer head. 
Triceps, long head. 
Triceps, in . head. - - 
Olecranon proc 
hit.cond.of hum:' 
Bicipital fascia.-' ^ 
Latissimus dor si."' 
Flex, carpi radialis. 
Flexor carpi ulnar is 

External oblique.' 
Lumbar aponeur/ ' 

Jliac crest.' ' 
Tensor fasciae fem^ 

Glutais medius.- 
Trochanter major. ' 
Post sup.i line spine. 
Gluteus maximus. ' 

Vastus cxternus. 

Ilio-tibial band. ^ 
Rectus fern or is tendon.' 

Patella. 

J lio- tibial band. 

Ligamcntum patellae. ' 

Tibialis anticus 

Long ex ten sor of toes. . 

L/tng extensor of great toe. 




Spine of 

VU cervical vertebr 

^ Trapezius. 
- ' ' '^ - Spine of scapui 

'" ,Deltoid. 

,- Infra-spinatt 

Xeres major. 
Triceps, long hea 

Triceps, outer hea 

, ^ 'Latissimus dor. 

^ - Triceps tendon. 

Triceps, inner hei 

^ Olecranon proce 

" _ ,— Internal cond} 

__- Post sup. iliac 

Bicipital fast 

- - Flexor c. nlna; 
-Posthor.oful 
-Flex.offingt 

^,, Styloid proc 
oful 



Biceps cruris, long hi 
_ . Vastus exteri 

.Biceps cruris, short lu 

^Biceps cruris tern 

_ _^^ Popliteal sj. 

^^^-Headnf fil 

, ^ Gastroc outer h 
' ' . , .Peroneus Ion 

- ' ' , - Soleus, 
. ' ' ^Peroneus bf 

'' ^ Tend a Ach 

External malit 



External annular lig^^ 



Movements of Column 55 

This sufficiently proves how limited the movement of rota- 
tion is when strictly confined to the column, and demon- 
strates how much the range of this movement depends upon 
the rotation of the pelvis on the thighs, for the head is now 
turned so that the eyes may be directed straight behind the 
figure, instead of across the shoulder, as happened when 
the movement was confined to the trunk alone (Pis., pp. 
52, 54, 86. 



CHAPTER IV 

THE THORAX, THE REGIONS OF THE FLANK, AND 
THE ANTERIOR ABDOMINAL WALL 

Although the chest-wall comes into immediate relation 
with the surface of the body at comparatively few points, 
it is an extremely important factor in determining the 
general outline of the upper part of the trunk, because it 
forms the framework which supports the bones of the 
shoulder-girdle. These bones impart a varying width to 
the shoulder, according as they are placed upon a narrow 
or a broad chest, a dilTerence which is characteristic of the 
two sexes, the comparatively narrow thorax of the female 
contrasting with the broad expanded chest of the male. 

In examining the structures which enter into its formation, 
it is necessary to consider what are the requirements of the 
chest-wall. In the first place it must be capable of move- 
ment. This depends on its association with the respiratory 
function. The chest-wall expands and contracts with a 
bellows-like action, which is effected by means of a series 
of jointed bones acted on by muscles. 

But, in addition, it is necessary that the chest-wall should 
form a protective covering for the vital organs which are 
lodged within its cavity ; for this reason, besides being 
movable, it must combine strength with elasticity. Its 
structure is admirably adapted to meet these require- 
ments ; bone, cartilage, ligament, muscle, and membrane, al] 
enter into its formation. 

The osseous framework consists of twelve pairs of ribs 
which vary in length and in degree of curvature, according 
to the position thoy occujiy. A typical specimen exhibits 



Ribs 



57 



a shaft which is more or less curved and twisted ; the 
posterior extremity or head articulates with the dorsal 
vertebrae ; and the anterior end is connected in front with 
the breast-bone by means of a bar of cartilage. 

If an articulated skeleton be examined, it will be noticed 
that all the ribs are not similarly connected with the breast- 
bone. The first seven pairs are joined to it directly by 



U b 





Fig. 33. The first and 
sixth ribs. 

a. Head. 6. Neck, 

c. Tubercle. d. Angle, 

e. Shaft. 
/. Extremity of shaft which 

articulates with the rib 

cartilage. 



Fig. 34. Shows how the ribs articulate 
with a vertebra as seen from above. • 

a. Head of rib articulating with body of vertebra. 

b. Neck of rib. 

c. Tubercle of rib articulating with transverse 

process of vertebra. 

d. Body of vertebra. 

e. Articular processes of vertebra. 

/. Neural ring for lodgement of spinal cord. 
fj. Transverse processes of vertebra. 
U. Spinous process of vertebra. 



means of their cartilages ; the next three pairs, namel}' 
the eighth, ninth, and tenth, are only indirectly united 
with it by pieces of cartilage- which are blended together, 
but which fuse above with the cartilages of the seventh 
pair of ribs ; while the two lowest, viz. the eleventh and 
twelfth pairs, are not connected with the breast-bone at all. 
The ribs are thus classified, according to their relation to 
the sternum, into the true ribs, which include the first seven 



58 



11 External condyle. 

12 Olecranon process. 

1 3 Ext. c. rod. longior. 

14 Atuoneus. 

1 5 ExL c.rad. brevier . 

1 6 External obliqzie. 

17 Post, border of Jilna. 
IS Extensor co7n. digit. 
\^ Pit of stomach. 

Sterno-mastoid.- 
Trapezius,- 

Ctavicle.- 
Df.ltoid.---. 

2 

4 
19. 
6- 
9> 
6x 

7v 
8. 

16., 
13. 
11-. 
12 „ 
15,, 
18- 
14 

Iliac crest. - 
r.xtenc uln. 
Ant sup.il sp 

(jlutais med. 
Tensor fuse fern 
7 rochaiitcr maj 
Aponeur. ext.ohl 

Poupart's lig. 

Iliopsoas^ 

Pectineus. . 

I liv-ttbuil band. 

Rectui femoris. 

A dducL/ongus .- 
Vastus exter. 
Gracilis. " 
Vditus internus. - - - 
Sartorius. 



Pit of neck. 
Pectoralis major ^ clavicular fbres. 

Breast bone {sternum). 

Pectoralis major, sternal ^bres. 

Triceps, outer head. 

Biceps cubiti. 

Brachialis anticus. 

Triceps tendon. 

Rectus abd. and Lineae trans. 

Supinator longus. 10 

-Slerno-mastoid. 
Trapezius. 

Clavicle.- 
■Deltoid. 

1 

2 




Ribs 



59 



pairs, and the false ribs, which comprise the lower five pairs. 
The latter group thus includes the two last pairs, which 
are generally known as the floating ribs. 

Arranged one above the other, these arched bones form 
a cage-like structure by their union with the breast-bone in 
front, and the column behind. The shape of the framework 
so formed has been referred to as a truncated cone, or it may 
be described as barrel-shaped. It is narrowest above where 
it lies in relation to the root of the neck, broadest about 
the level of the pit of the stomach, or lower end of the 
breast-bone. Below this level it again narrows slightly. 
The length and curvature of the ribs naturally vary 
according to their position ; thus the first pair of ribs is the 
shortest and the most bent, the seventh or eighth pairs 
are the longest and most open in their curve. The ribs 
are not uniformly curved : if one of the middle ribs bo 
examined, it will be seen to possess two curves ; these 
are not in the same plane, but in planes placed obliquely 
to each other, so that where the curves meet an angle 
is formed not only between the curves themselves but 
between the planes of the curves ; this angle has been 
already referred to in connexion with the study of the 
vertebral column ; the part of the shaft of the rib behind 
it has been seen to assist in the formation of the groove in 
which the erector muscles of the back are placed; the part 
of the shaft of the rib in front of the angle forms the curve 
of the side and front of the chest-wall. The adaptation of 
the ribs to the barrel shape of the chest-wall necessarily 
involves a slight twisting of their shafts, so that the 
flattened surfaces of these bones are brought into harmony 
with the general outline of the thorax. 

The breast-bone or sternujn, in the adult, consists of three 
pieces, the middle one of which has been formed by the 
fusion of several elements. These three parts of the 
breast-bone may be inseparably united, but it is usual to 



6o 



Ribs and Thorax 



find the highest one detached from the others in the 
macerated skeleton. As the joints which unite these parts 
in life are so firm that there is practically no movement in 
them, we may for present purposes regard the sternum as 
one bone consisting of three parts, an upper, a middle, and 
a lower. Viewed from the front the upper part appears 




Fio. 35. Front view of skeleton of thorax. The costal cartilages 

are shaded. 

the largest and most expanded ; the middle portion displays 
much variety of shape in diflerent individuals: it varies 
in width, and is often considerably wider below than above. 
The joint between the upper and middle parts of the bone, 
if fu.sion has taken place, is marked by a transverse ridge.' 
The lowe.st part consists in early life of cartilage, which 



Brcast'bone 



6i 



bscomes ossified later ; it also varies mucli in shape, and its 
anterior surface does not come as far forward as the level 
of the front of the middle part. 

If we examine the bone from the side, we note that it is 
slightly curved, a curve whicli corresponds to that of the 
front of th.e chest-wall in the middle line ; above^ this 




Fig. 36. Side view of skeleton of thorax. 

are shaded. 



The costal cartilages 



curve is interrupted at the point of junction of the upper 
and middle portions by a slight angle formed by the 
articulation between the two. This is known to anatomists 
as the sternal angle. (See Fig. 38.) 

As has been already seen, the breast-bone is of great 
service in forming a support for the ribs in front, being 



.J- 



Postborder 
of ulna.... 



Bicifiit. 
fascia. . 



Sty /old process of ulna. 
Flexor carpi ulnaris. 
■Flex, of fingers. 



.Flex.c.rad. 



Pronator 
Sterna 

Clavicle. 
Trapezius: 
Deltoid. 



ter. 
tnast. 



-fj 



Olecran: 
Intcond 

Biceps ■■'' 
Brach.ant: ' ' 
Triceps in. ltd:'' 
long headr ' ' 
Coraco-brachialis: 

Teres major:' 
Latissimus dorsi:' , 
Axilla:' 
Pectoralis major.'' 
Breast bone {^sternum):' 
Serratus magnus:' 
External oblique. - 
Rectus tendintersections.- 
Iliac crest. -- 
Gluteus medius.— - 
Anterior sup. iliac spine: ' ' 
Tensor fasciae fenwris. - - - ' 
Trochanter major. 

Poupart's ligament:' 

Ilio-tibial band. 

Sar tonus. -. 

Rectus femoris. 

Vastus externus. 

Band of Richer. . . 
Vastus internus.- - - 

Patella. -. 
Tendon of Biceps cruris — 
I lio-tibial band: ■ ■ 
Ligamentum patellae. 
Head of Fibula-. ■ 
Soleus: - 
Gastrocnemius, inn^r head: - 
/ ibia, subcutaneous surface:-- 
Soleus. - 
Peroneus longus:- 
Tibialis anticus: 

Peroneus brevis. 

Long extensor of toes.- 

I-ong extensor of great toe: - 
Annular ligament of ankle: 
I'.xlernal walleolus: 
Tendon of Peronni\ iertius: ' 
Tendons of long extensor of toes 



U^ 




-Int. 
coTtdylc 
of jemurr 



Int. malleolus. 

7 cndun of 
Tibialis ant. 

Abductor of great toe 



Sterno-mastoid. 

Clavicle. . 
/ Trapezius. 
'' / jPectoralis major, clavicular fibres^ 

'' / Peltoid. 
/ / Pectoralis major, sternal fibres 

/ / Coraco-brach. 
/ / -' Biceps 
/ / / Flex.digif 
Flex.c.rad. 

Prou.ter, W'/Z/zl « 

. , F'lexor 
carpi uln 
'■^__ . bicipital fa sc 
- -Brachialis ant 
"Internal condyle 
">, \ \'; '''Olecranon process 

\ 'Triceps, bngand inner head. 
, \ Teres major. 
"•, Latissimus dorsi. 
-, Serratus magnus. 
External oblique. 
'Rectus abdominis. 
--■Iliac crest. 

- -Anterior superior iliac spine. ■ 
'-Aponeurosis of external oblique. 
—Tensor fasciae femoris . 

Ilio-psoas. 

-Pectineus. 

Sartorius. 

- A dductor longus. 

Qyacilis. 

- -Rectus femoris. 
-Vastus externus. 

— Vastus internus. 
. - -Band of Richer. 

. . -Rectus femoris tendon. 
..--'Sartorius. 
.-Patella. 
'[..-Fat 
' ..- -Ligamentu?n patellae. 

Ilio-tibial ba?id. 

■ Tubercle of tibia. 

-- Gastrocnemius jnjier hd. 

- -Tibia, subcutan. surf dee. 

- -Tibialis anticus. 
- Soleus. 

- Long flexor of toes. 
Tnternal malleolus 

. Tendon of Tib. ant 

Tend.of Tib. post. 

-Tendon of 

Long extensor 

of great toe 



Breast-bone 



63 



united to them by the rib cartilages already referred to. 
The first pair of ribs articulates with this bone at the 
upper angles of the highest portion ; the second pair of 
ribs, by means of their cartilages, unites with the bone on 
either side, at a level with the line of articulation, or it 
may be of fusion, of the highest segment with the middle 
portion. The third, fourth, fifth, and sixth pairs of ribs 



^ i/>^\^ -• 


s 


=1;.^.:: 


::.4-'nyr!^^::: 


yMs 




Breast-bone (sternum). 



Fig. 37. Front view. 

a. Upper part of breast-bone (manu- 
brium sterni). 

6. Middle part of breast-bone (body, or 
gladiolus). 

c. Lower part of breast-bone (ensiform 
process). 



Fig. 38. Side view. 

d. Surfaces for articulation with collar- 

bones. 

e. Surfaces for articulation with cartilage 

of first rib. 
i. Surfaces for articulation with carti- 
lages of second to seventh ribs inclusive. 



are united to the middle part of the bone along its outer 
border, and the seventh pair of ribs, i. e. the last pair directly 
connected with the sternum, is wedged in between the 
middle and lowest portions of the bone. 

In addition to its connexion with the ribs, the breast- 
bone also articulates with the collar-bones; the surfaces 
for these may be seen at the upper angles of the first 



64 Breast-bone 

portion, just above the point where the first ribs are 
attached. The upper border of the first part of the breast- 
bone between these two articular surfaces for the collar- 
bones is thick and rounded and slightly hollowed ; it 
forms the lower limit of that depression familiarly known 
as the pit of the neck (Pis., pp. 58, 148, 152, 382). From this 
point downwards along the middle line the bone is quite 
superficial and corresponds to a groove, noticeable on the 
model, the sides of which are formed by the bulging of the 
powerful muscles which arise from the lateral surfaces of this 
bone. If the finger be run down this groove, the sternal 
angle, formed, as has been said, by the articulation .of the 
highest and middle portions of the breast-bone, can always 
be recognized by touch, and in the male not unfrequently 
by sight. Inferiorly the groove ends in a more or less 
well-marked depression over the situation of the lowest 
segment of the bone, or ensiform cartilage as it has been 
named. This depression is called the pit of the stomach, 
and its sides are formed by the slight projection of the carti- 
lages of the seventh pair of ribs as they pass upwards to the 
breast-bone (Pis., pp. 58, 62, 72, 158, 382). 

In the female these details are obscured by the large 
deposition of fat in this region, due to the presence of the 
breasts (Pis., pp. 72, 86, 132, 298). The extent to which these 
points can be observed in persons of either sex will largely 
dopond on the degree of muscular development and the 
amount of fat. In an emaciated person not only can the 
outline of the whole breast-bone be seen, but the ribs and 
rib cartilages may with ease be counted. 

From the fact that the ribs are articulated with the back- 
bone in such a way that their posterior extremities always 
lie on a higher level than their anterior ends, the shaft of 
each bono lies in a plane oblique to, and not at right angles 
witli, iho vortical piano. In consequence of this, the upper 
end of the breast-bone does not lie on a level with the 



Thorax 



65 



first thoracic vertebra, but at a point considerably below, 
corresponding it may be to the lower border of the second, 
or the upper border of the third, thoracic vertebra ; the level 
varies slightly according as the breast-bone is raised or 
lowered during the respiratory movements (Fig. 39). It is 
due to this obliquity of the first rib that the neck appears 
longer in front than behind. In like manner the lower end 
of the middle segment of the sternum corresponds usually 
to the level of the ninth or tenth thoracic vertebra. Of 
course this will vary according to the length of the bone, 
which differs considerably in dif- 
ferent individuals. The angle which 
the bone forms with a horizontal 
line drawn through its inferior ex- 
tremity ranges from about 70° to 75°; 
in the female the bone approaches 
more nearly the vertical position. 
In the male, the upper part of the 
breast-bone is relatively shorter and 
broader than in the female, whilst 
the middle part is proportionately 
longer and narrower in the male 
than in the female. The absolute 
measurements will of course vary 
with the heights of the individuals 

examined. In regard to the proportionate length of the 
sternum, Duval has pointed out that, including the upper 
and middle portions only, it corresponds pretty closely to 
the length of the collar-bone or to the length of the hand 
less the third joini; of the middle finger. 

Taken as a whole, the thorax in the female is of slighter 
build and relatively shorter and more rounded than in the 
male ; in the female, too, the upper ribs are more movable 
than in the male, an arrangement which allows of greater 
expansion of this part of the female chest during violent 




Fig. 39 (after Quain). 
Illustrates the rise and 
fall of the chest-wall in 
the movements of respira- 
tion. 



66 Thorax 

inspiratory movements, such as are very frequently employed 
on the stage to indicate suppressed emotion. The lower 
margin of the thorax plays an important part in the 
moulding of the surface contours. The eleventh and 
twelfth ribs may be disregarded, for their shafts and ex- 
tremities are deeply imbedded in the fleshy muscles of the 
flank, but the cartilages of the tenth, ninth, and eighth 
ribs, as they curve forward and upward to join the cartilages 
of the seventh ribs, and thus become indirectly united with 
the breast-bone, are very clearly indicated on the surface 
of the body, though their outline may be concealed to 
a greater or less extent by the development and state of 
contraction of some of the muscles which form the wall 
of the abdomen in front (Pis., pp. 72, 148, 152, 158). 

The form of the outline so described sweeps downward 
and outward from the pit of the stomach, in a direction 
towards the highest point of the crest of the haunch-bone ; 
the convexity of the curve being directed inwards and 
downwards. As will be shown hereafter, the acuteness of 
the angle between the two converging borders of the 
thoracic wall is to a great extent concealed by the presence 
of two of the muscles which form the wall of the abdomen 
in front. These are called the recti abdominis muscles, and 
arc placed one on either side of the middle line. 

As already stated, the expanded outer surface of the 
tlioracic wall affords extensive attachment, not only to 
the muscles of the abdomen, but also to the muscles of the 
upper limb. In this way the outer surface of tl;e ribs is 
clothed with fleshy layers, which conceal the form of these 
bones, whilst the shoulder-girdle above, with its associated 
muscles, entirely modifies the shape of the upper part of the 
trunk. 

The rogion of the abdomen, which we have next to 
consider, lies between the lower thoracic margin above and 
the pelvis belf)W. It extends round the sides of the trunk, 



Anterior Abdominal Wall 



67 



where it forms the flanks, and there its surface-form blends 
behind with that produced on either side by the erectores 
spinae muscles. A longitudinal furrow along the outer 
border of that fleshy mass in the lumbar region serves 
to define the hinder limit of the flank (Pls.^ pp. 38, 44, 50, 98). 

The cavity of the abdomen, however, is not so limited, 
but extends upwards beneath the thoracic wall for a con- 
siderable distance, its roof being 
formed by a dome-shaped partition, 
the diaphragm, which separates it 
from the thoracic cavity. 

The anterior aspect of the ab- 
dominal wall is limited above, in the 
middle line, by the pit of the stomach, 
a depression which corresponds to 
the ensiform cartilage. From this 
point its margin is defined by the 
cartilages of the seventh, eighth, 
ninth, and tenth ribs in the manner 
already described ; the eleventh and 
twelfth ribs, though not discernible, 
and as a rule with difficulty felt, carry 
this curve towards the back. 

The lower boundary of the ab- 
dominal wall is formed by the haunch- 
bones. These bones will be more 
fully described when the anatomy of 
the thigh and buttock is considered, 
but it is necessary here to mention some points connected 
with their structure. As was stated in an earlier chapter, the 
haunch-bone is formed by the fusion of three smaller bones, 
the ilium, thepubis, and the ischium. "With the first two only 
are we at present concerned. The ilium forms the upper 
expanded wing-like portion of the haunch-bone, and by its 
inner hollow surface furnishes a support for the contents 

F 2 




Fig. 40. Diagram show- 
ing the boundaries of the 
abdominal region. 

a. Anterior superior iliac 

spines. 

b. Symphysis pubis. 

c. Poupart's ligament. 

d Outline of lower thoracic 
margin. 

e. Ensiform process corre- 
sponding to the pit of the 
stomach. 



68 Haunch-bone 

of the abdominal cavity, while the outer aspect affords 
attachment to the muscles of the buttock. These two 
surfaces meet above, and form the upper curved margin 
of the bone, which is termed the crest. This ' iliac ' crest 
ends, in front and behind, in two well-marked projections 
or spines, called respectively the anterior and posterior 
superior iliac spines. The relation of the latter we have 
already studied in connexion with the surface forms of 
the lower part of the back (vide Chapter III). The anterior 
superior iliac spine will be found to have a like importance 
in relation to the anterior region (Pis., pp. 58, 62, 72, 86, 
148, 152, 158, 216, 298, 318, 366, 438). 

The pubis is that portion of the haunch-bone which lies 
in front and below. The pubis of the one side is united to 
its fellow of the opposite side by an immovable joint called 
the symphysis pubis, which corresponds in position to the 
lower part of the abdomen, in the middle line. An inch 
or so from the middle line (somewhat more in the female), 
the upper border of this bone forms a projection, called 
the sjjine of the pubis. Stretching between the anterior 
superior spine of the ilium, which lies at a considerably 
higher level, and the pubic spine there is a band of fibrous 
tissue, called Pouparts ligament. This band, which is in 
reality formed by the lower fibres of the sheet-like tendon 
of one of the abdominal muscles, is curved between its 
points of attachment. The convexity of the curve is 
directed downward, and corresponds to the furrow which 
separates the lower abdominal region from the front of 
the thigh ; the furrow is commonly known by the name 
of the ibid of the groin. 

Such are the boundaries of the abdominal wall. Now 
this wall is made up of a number of expanded sheet- 
like muscles attached by their edges to these boundaries, 
and in order to understand better the arrangement of 
these structures it will bo of advantage to study a dia- 



Muscles of Abdominal Wall 



69 



grammatic representation of a cross-section of the trunk 
(Fig. 41). 

Connected with tlie lumbar vertebrae are sheets of con- 
densed fibrous tissue (aponeuroses). These layers, which 
spring from the spines and transverse processes in the 
manner represented in Fig. 41, unite wide of the middle 
line, and just external to the erectores spinae muscles so as 
to encase these muscles in a fibrous sheath. From the strong 




Fig. 41. Diagram of a section across the trunk to illustrate the 
arrangement of the muscles of the abdominal wall. 



a. The sheath of the rectus abdominis 
formed by the tendinous aponeuroses 
of the muscles of the flank. 

h. The rectus abdominis muscle in situ. 

C. The external oblique muscle, the most 
superficial of the three muscles of 
the flank. 

d. The compartment formed by the 



splitting of the lumbar aponeurosis, 

within which is lodged 
e. The erector spinae muscle. 
/. The quadratus lumborum muscle, 

lying within 
g. Another comimrtment formed by the 

splitting of 
i. The lumbar aponeurosis. 



h. The body of a lumbar vertebra. , 

aponeuroses so constituted, certain of the muscles of the 
flank take origin. Their fleshy fibres are so disposed that 
three muscular layers are formed, the direction of the 
fibres of which vary widely. The outer layer constitutes 
the muscle known by the name of the external oblique; the 
other two layers are from without inwards, the internal 
oblique^ and transversalis. The fleshy fibres of these three 
muscles do not reach far forwards on the abdominal wall, 



70 



Lumbar Aponeurosis 



but are again replaced by tendinous sheets or aponeuroses ; 
as we approach the middle line in front, the aponeurosis 
of the intermediate muscle splits, the split layers being 
united in front and behind with the aponeuroses of the 
outer and inner muscle respectively. The layers so formed 




Fir;. 42. Side view of muscles of the trunk. 



a. Pf'otoralis major muscle. 

h. KxtiTual obliijuc muscle of abdomen. 

c. A|)Oi»ourosi8 of external oblique, cor- 

roHpondinjf to linea semilunaris. 

d. Aponeurosis of external oblique, pass- 



ing in front of rectus abdominis 

muscle. 
e e. Anterior superior iliac spine, Pou- 

part's ligament, and spine of pubis. 
g. Serratus magnus muscle. 



h. Latissimus dorsi miiscle 

enclo.se a muscle which is here represented in section, the 
fibres of whicli are directed longitudinally. This is the 
HiniKjht or redm muscle of the abdominal wall. At the side 
of llii.s muscle;, nearest the middle line, the layers which 
overlie it back and iVout agjiin unite, and become blended 



Abdominal Wall 



71 



with a similar la^^er from the opposite side of the body. As 
both sides of the trunk are symmetrical, there is formed 
in this way a fibrous cord, which lies^ in the middle line in 
front, extending from the cartilage of the breast-bone above 




Fig. 43. Front view of muscles of the abdominal wall. 



a. Pectoralis major muscle. 

h. External oblique muscle of abdomen. 

c. Aponeurosis of external oblique, cor- 

responding to linea semilunaris. 

d. Aponeurosis of external oblique, pass- 

ing in front of rectus abdominis 

muscle, 
e t. Anterior superior iliac spine, Pou- 

part's ligament, and spine of pubis. 
/. Rectus abdominis muscle, exposed by 



k. 



tho removal of the front of its 
sheath, and showing its tendinous 
intersections. 

Serratus magnus muscle. 

Latissimus dorsi muscle. 

Linea alba, formed by the fusion of 
the tendinous aponeuroses of the 
muscles of the flank in the middle 
line. 

Umbilicus or navel. 



to the symphysis pubis below ; this is called the linea alba. 
On either side of this are the longitudinal recti muscles, 
which also stretch from the thoracic margin above to the 
pubis below. These muscles are enslieathed in the manner 
iust described. 



SUmo-mastoui- 



Trapezius. 



Clavicle. Acromion process of scapula 



.Deltoid. 




Clavicle. 

Pfctoralis major 

Deltoid. 

Curaco-briichialis. 

Latissimus dorsi 

iJigttolwus of serratus 
maptus. 
Triceps, long head. 
Triceps, outer head. 
Triceps, inner head. 

Biceps cubifi. 

Brcuhialis anticus. . 

Rectu s t: hdom inis: ■'" 

Gluteus medms. 

Internal condyle 

Bicipital fascia ' ' 

Pronator radii teres:"\ 
Supinator longus."" 
Ext. carp. rod. long.' ' 
Ext. carp rad.brevr' 
Flexor carpi radialisf 
Extensors of thumb.- ' 

Gracilis 

Rutus femoris 

/ 'astus ex tern us. 
Vastus internus 
Internal condyle of femurt 

Sartortus. " " 

Gaitrornemius, inner head 
Tibialis nntieus 

Jibia, iubcutaneous surface. 

Soleus. 

Elrxor lonpii di^itorum pedis. 
Extensor lonpn digttorum pedis. 

Umg txtenior of great tot 



''' Pectvralis major, 
■ ■ ' clavicular ^bres. 

^Triceps, outer luad. 

^Brachialis anticus. 
..Biceps cubili. 

...Latissimus dorsi. 

Pectoralis major. 

sternal fibres. 

upinator longus. 
—Digitations of 
serraius mag. 
Ext. carp. rod. 
long. 
Ext. car p. ,r ad. 
breu 
Ext. com. 
dig- 
External 
obliipie, 

■Ltnea trans 

■Ant. sup, iliac \pine. 
"'•"Aponeurosis of 
• ... external oblique. 
'^'•.Linea alba 
. . ■■ Tensor fasc. fan. 
'"•^..Itto-psoas. 
""'-Pectineus. 
'Adductor longus 
Ilio-tibial band. 

Sartorius. 

: • ■ ■ Rectus femoris- 

..' Vastus c.vternus 

Gracilis. 

Vastus internus. 

Band of Richer. 

Ilio-tibial band. 

■.-Patella. 

Fat. 

Ligamentum patellae. 

Soleus. 

Gastrocnemius, 

inner head. 

Peroneus longus 

Extensor longus dig, ped. 

- Tibialis anticus. 

ibia. subcutaneous surface. 

-Peronats brevis. 

Long extensor of great toe. 
Internal malleolus [tibia) 
nnular ligament of anklo 
External nial. 





4 





1 




m 




1 





k 



External Oblique 73 

"We are only concerned with the most superficial of the 
muscles of the flank and abdominal wall. This is the 
external ohlique ; as its name implies, its fibres have an 
oblique direction. The muscle consists of a broad sheet of 
fleshy fibres which takes origin from the outer surfaces of 
the eight lower ribs, by a series of slips or digitations. The 
hinder fibres, almost vertical in direction, pass down to be 
attached to the anterior half of the crest of the ilium or 
haunch-bone. In front of this attachment the fleshy fibres 
are inserted into the most superficial of the aponeurotic 
layers just described. These anterior fibres are directed 
forwards with varying degrees of obliquity." Through the 
medium of its aponeurosis the muscle becomes attached to 
Poupart's ligament (which has been already described as 
passing between the anterior superior iliac spine and the 
spine of the pubis) , to the whole length of the linea alba, 
extending from the symphysis pubis below to the cartilage 
of the breast-bone above, and to the fascia covering the 
large muscle which arises from the front of the chest- wall 
on either side of the middle line, viz. the muscle called the 
great pectoral. A line let fall vertically from the middle 
of the collar-bone to meet a transverse line carried across 
between the two anterior superior spines of the ilia, with 
the angle between the two rounded off, will fairly accurately 
define the anterior and lower limits of the fleshy portion 
of the muscle (Figs. 42, 43). 

The recti muscles of the abdomen lie on either side of the 
middle line ; they are attached above to the cartilages of 
the fifth, sixth, and seventh ribs, as well as to the cartilage 
of the breast-bone ; below they are connected with the pubes 
and pubic symphysis ; their lower attachments are very 
much narrower than their upper. These muscles do not lie 
immediately beneath the skin and superficial fatty layer, 
but are ensheathed, in the manner already stated, by the 
aponeuroses of the muscles of the flank. When the anterior 



-74 Rectus abdominis 

layer of these sheaths is removed, the muscles are exposed. 
The arrangement of their fleshy fibres is peculiar. In place 
of extending the whole length of the muscle, they are 
interrupted by tendinous intersections which usually occupy 
certain definite positions. In this way the muscle is not 
composed of one fleshy belly, but of four or five segments 
firmly united to each other by short tendinous fibres. These 
tendinous intersections, or lineae transversae, as they are 
called, are usually three in number, and are situated, the 
lowest, a little above the level of the navel ; the highest, 
a short distance below the pit of the stomach ; the inter- 
mediate one, midway between the other two. The latter 
is usually continuous, towards the outer side, with the broad 
shallow furrows which surround the sides of the trunk, and 
which mark the position of the waist (Fig. 43, and Pis., pp. 
58, 62, 86, 148, 152, 158). 

The inner borders of the two muscles lie side by side, 
being separated merely by their sheaths and the linea alba, 
whicii is wider above the navel than below. The outer 
border is gently curved from the upper broad attachment 
to the more pointed lower origin from the pubis. 

Wo must now examine the influence these structures 
have upon the surface contours. A median furrow is seen 
running from the pit of the stomach downwards towards 
the symphysis pubis; this corresponds to the position of 
the linea alba. The prominence of the rectus muscle on 
either side assists in deepening the groove. About midway 
between the cartilage of the breast-bone and the symphysis 
pubis is placed the 7iavtL Below this point the median 
lurrow becomes less distinct, and finally disappears owing to 
the closer approximation of the recti muscles and the more 
al>undant quantity of fat in this region (Pis., pp. 58, 62, 72, 
86, 148, 152, 158). 

'i'ho out(5r borders of the recti muscles are marked by the 
existence of furrows, sometimes called the lineae semilunares. 



Coritours of Abdominal Wall 75 

These separate the anterior abdominal region from those 
of the flanks. Commencing above at the costal margin, 
just wide of the attachment of the recti muscles to the ribs, 
these furrows are narrow, as here the fleshy parts of the 
recti and external oblique muscles lie close together. At 
the level of the navel the furrows begin to widen, and 
ultimately spread out to form smooth areas of triangular 
shape. These areas correspond to the surface of the ab- 
dominal wall immediately above the folds of the groin. 
Here the fleshy parts of the superficial muscles of the 
abdominal wall are separated by a wide interval com- 
posed of tendinous fibres. The outer border of the rectus, 
as it curves in to be attached to the pubis, limits this 
region on the inner side. Its lower boundary is marked 
by Poupart's ligament. Above and to the outer side, 
the fibres of the external oblique form its outer limit. 
These details may not in every case be clearly recognized, 
as their sharpness depends on the quantity of fat beneath 
the skin (Pis., pp. 58, 62, 148, 152, 158). 

A glance at Fig. 43 will enable the reader to realize that 
this triangular area corresponds to the lower part of the 
aponeurosis of the external oblique muscle, which here 
has a form somewhat resembling the shape of an arrow- 
head, the point being directed towards the spine of the 
pubis; the sides, to the outer border of the rectus and 
Poupart's ligament respectively ; the tang, or part where 
the arrow-head is connected with the shaft, corresponding 
to the insertion of the fibres of the external oblique. 

The prominences formed by the recti muscles as they lie 
between the median and lateral furrows are interrupted by 
transverse grooves. Above the level of the navel these 
grooves are due to the presence of the lineae transversae 
which were described in connexion with the recti. The 
sheaths of these muscles are not thick enough to obscure 
the influence of these tendinous intersections ; besides, there 



76 Contours of Abdominal Wall 

is an intimate union between the anterior part of the 
sheath and those tendinous fibres, so that their position 
is rendered very evident by the occurrence of transverse 
grooves on the surface of the body when the muscles are 
powerfully contracted. Their position has been already 
sufficiently indicated, but it may be well to refer to their 
modifying influence on the outline produced by the lower 
thoracic margin. Where the recti muscles are attached 
to the cartilage of the fifth, sixth, and seventh ribs, they 
necessarily overlie the cartilages of the seventh ribs, and 
according to the varying thickness of the muscles (de- 
pendent on the degree of their development) the surface 
form produced by the cartilages of the seventh ribs will be 
obscured. This accounts for the fact that the angle formed 
by the converging margins of the chest-wall at the lower 
end of the breast-bone is not so evident as a mere inspection 
of the skeleton might lead us to suppose. On the other 
hand, the highest of these transverse furrows which cross 
the recti lies some distance below the pit of the stomach. 
Its outer extremity usually corresponds to the junction of 
the eighth rib cartilage with the seventh; and the two 
furrows, one on either side, form an arch across the middle 
line, the convexity of which is directed upwards. This arch 
cuts off the acute angle formed by the converging cartilages 
of the seventh ribs. Externally this furrow joins the lateral 
abdominal furrow, or the furrow between the rectus and the 
(ixtemal oblique, which here corresponds to the lower costal 
margin, and it is the contour so produced which obscures 
the form of the lower costal border on the anterior aspect 
of the trunk. The extent to which this occurs will of 
course depend on the muscular development of the model 
(Pis., pp. 58, 148, 152). 

The fold of the groin, as has been seen, corresponds to 
the position of Poupart's ligament. Owing to the fact that 
tins l)aiid is V(a'y intimately connected with the fascia or 



Fold of the Groin 



11 



investing fibrous sheath of the thigh, it is found to undergo 
considerable modification according to the position of the 
limb. Thus, when the thigh is extended or straightened 
on the trunk, the fascia which invests it will necessarily 
be drawn down, and as one of the attachments of this 
fascia is Poupart's ligament the result is that the ligament 




Fig. 44. Diagrammatic representation of the various furrows and 
depressions on the anterior surface of the trunk. 

is rendered more tense at the same time that its downward 
curve is increased. If, however, the thigh be bent upon 
the trunk, the ligament is relaxed and tends to become 
straighter ; these facts react on the surface form (Pis., pp. 
38, 382). When the limb is extended the fold of the groin 
will be seen to best advantage and will display a more or 



^8 Fold of the Groin 

less curved outline, a form which is always accentuated in 
the antique (Pis, pp. 148, 152, 158). The outer end of this 
furrow corresponds to the position of the anterior superior 
iliac spine, at which point it forms an open angle with 
the transverse furrow of the flank ; the inner extremities 
of the folds of the groin are not unfrequently lost in the 
fat in this region, though in many cases they become 
blended with a shallow depression which curves down- 
wards across the lower part of the abdominal wall and 
the prominence which overlies the symphysis pubis. Owing 
to the fact that in the male the pelyis is relatively narrower 
and deeper, the furrow of the groin is more oblique and 
more nearly approaches the vertical, whereas in the female 
with the shallower and wider pelvis the furrow inclines to 
be more horizontal in position (Pis., pp. 72, 148, 158, 216, 
298, 434). Just above the furrow, in the female, there is 
frequently a second shallow curved depression, as seen 
in the Townley Venus, and in Fig. 45, and Pis., pp. 72, 
298. 

Distinct from the above, and due to the flexion of the 
thigh at the hip-joint, there is a crease or superficial folding 
of the skin which lies below the fold of the groin, and is 
best seen in the plump thigh of a young child. This line 
is most distinct internally, by the side of the genitals, 
and curves upwards and outwards across the upper and 
anterior part of the thigh to be lost in the general round- 
ness of the limb or accentuated by a dimple overlying the 
interval between the sartorius and tensor fasciae muscles 
of the thigh immediately below the anterior superior iliac 
spine (PI , p. 298). In the adult it is best seen in the 
female, in whom its inner extremity is not concealed, as 
in the male. Briicke has pointed out that in the female 
this lino appears in two distinct forms. In the one, as 
shown in Fig. 46, the hollow of the curve is directed 
upwards, the outer cxtromity of the furrow is tm^ned 



Differences between Male and Female 79 

towards the anterior superior iliac spine, and it usually 
blends with the fold of the groin about its middle. In 
the other type (Fig. 45) the line curves outwards across 
the thigh, the hollow of the curve being directed down- 
wards. Externally the line is in some cases but faintly 
seen on the general jrounded surface of the front of the 
thigh (Pis., pp. 72, 158) ; in other instances, as above men- 
tioned, it is emphasized by a dimple (PI., p. 298), but if 
the thigh be flexed the fold is rendered more distinct. 
The abdomen in the male should be small ; that of the 





Fig. 45. 



Fig. 46. 



female, which is relatively larger, should be of rounded 
form and slightly more prominent, owing to the presence 
of a thicker fatty layer ; in the female also the surface 
contours dependent on muscles are obscured, and display 
a smoother and more rounded appearance. For the same 
reason the navel in women is usually more depressed, owing 
to the presence of the surrounding fat (Pis., pp. 72, 86, 158). 
One need not here dilate on the baneful influence of the 
pressure exerted by the use of corsets on the shape of 
the abdomen, it is sufficient merely to note the fact and 
put the student on his guard against the artificial forms 



8o The Flank 

so produced. In some models, however, an indulgence 
in athletic exercises may lead to such a development of 
the abdominal muscles as may modify the form of the 
abdomen and so render it more conformable to the mascu- 
line type. The model figured in plates, pp. 54 and 438, 
displays this appearance, and it is interesting to note that, 
according to her own statement, she never wore corsets. 

Turning next to that portion of the abdominal wall which 
lies between the lateral abdominal depression in front 
(i. e. the furrow corresponding to the interval between the 
rectus and external oblique) and the lateral dorsal depression 
behind, this is found to include the region known as the 
flank. Above, the thoracic margin limits this region ; below, 
the crest of the ilium or haunch-bone serves to define it 
from the buttock. The lower half of the sheet of fibres 
of the external oblique, already described, constitutes the 
most superficial muscle in this region (Pis., pp. 50, 54, 86, 
126, 152, 162, 308). 

The surface of the flank is rounded from before back- 
wards, and is marked off from the prominence of the buttock 
below by a furrow which is well defined in the muscular male, 
less so in the female (Pis., pp. 54, 86, 262, 270, 318, 438). The 
position of this furrow corresponds in front to the anterior 
superior iliac spine and also to an inch or two of the iliac 
crest ; behind this point, however, as indicated by E-icher, 
the attached fleshy fibres of the external oblique overlap 
the iliac crest so that the furrow, which depends largely 
on the development of these fibres, does not overlie the iliac 
crest, but is placed at a somewhat lower level. The furrow, 
which assumes towards its termination a somewhat upward 
curve, gradually fades away and is lost in the rounded form 
produced by the accumulation of a considerable amount of 
fat ; this obscures the outline of the posterior border of 
the external oblique muscle. In the female, on account 
of the greater amount of fat in this region, all trace of the 



The Flank 



8i 



upper lateral depressions, which we saw overlay the point of 
attachment of the fleshy fibres of the erector spinae to the 
hinder end of the iliac crest in the male, disappears (p. 45) 
(Pis., pp. 34, 52, 54). Owing to the obliteration of the" 
iliac furrow — as the groove we 
are just describing is called — by 
the presence of this pad of fat, 
the rounded surface of the pos- 
terior part of the flank is not so 
clearly defined from the general 
swelling of the buttock as in front, 
but is insensibly blended with it 
■ — a condition which maintains to 
a greater extent in the female. As 
will be seen in the accompanying 
figure (Fig. 47), the iliac furrow 
displays a double curve. Its an- 
terior extremity corresponds to 
the position of the anterior supe- 
rior iliac spine, a point occasion- 
ally more or less prominent, where 
it forms an angle with the furrow 
of the groin, as has been already 
stated. 

The upper limit of the flank 
corresponds to the waist, the 
narrowest transverse diameter of 
the trunk. Above this level the 
figure increases in breadth owing 
to the enlargement of the thoracic 

framework, and the muscles connected with the upper 
limb. Below, the outline is carried down by a gentle 
curve which increases the breadth of the trunk until the 
iliac crest is reached ; at this point, owing to the over- 
lapping of the iliac crest by the fleshy fibres of the external 




Fig. 47 (after Richer). 
Shows the relation of the 
iliac furrow to the iliac crest. 



THOMSON 



G 



82 



The Flank 



oblique, the curve is mucli accentuated as it dips down 
into the iliac furrow. In the female the outline is softer 
and more flowing, and the iliac furrow not so well marked. 
The waist, therefore, corresponds to a broad shallow furrow 
which lies between the wider parts of the trunk above and 
below; in front this shallow depression becomes blended 
with the lateral abdominal furrow or linea semilunaris, at 




Fig. 43. 

a point corresponding to the junction of the tenth rib 
cartilage with the ninth, at some distance above the level of 
the navel, and a trifle below the level of the middle trans- 
verso intersection of the rectus (Pis., pp. 62, 86). At this 
point, whore there is a slight general hollowing of the 
surface, the thoracic margin formed by the cartilages of 
the false ribs can bo distinctly felt, and corresponds to a 



Action of Abdominal Muscles 



83 



depression which is accentuated in certain positions (PL, 
p. 38), and is well displayed in the figure of Theseus from 
the pediment of the Parthenon. As is seen in many of the 
antiques, this furrow of the waist is carried round the front 
of the figure in correspondence with the furrows produced 
by the middle tendinous intersections of the recti (Pis., 
pp. 58, 148, 158). 




The abdominal muscles above described are of great use 
in supporting the contents of the abdominal cavity, and 
also assist in the movements of respiration. When any 
violent muscular effort is about to be made, these muscles 
are thrown into a state of contraction to brace up the 
abdominal walls, and so resist the strain to which they 
would otherwise be subjected. If the vertebral column be 



Q 2 



84 Contours of Abdominal Wall 

not fixed, these muscles will assist in bending the trunk 
forwards if the muscles of both sides act at the same ' 
time. If only those of one side are brought into play they 
will Qffect a lateral movement of the trunk towards the 
side on which they are contracted. It may happen that 
the upper part of the trunk is fixed, as in climbing or 
hanging by the hands ; in this case the muscles will assist 
in drawing upwards and forwards, or to one or other side, 
the pelvis and lower limbs. 

These movemeints give rise to very considerable modifica- 
tions in the surface forms. When the trunk is bent forward 
the tissues of the anterior abdominal wall become infolded 
(Figs. 48, 49; Pis., pp. 72, 382). The deepest of these trans- 
verse folds passes across the belly a little above or just on 
a level with the navel. Laterally this fold corresponds to 
the inferior thoracic margin, and the compression of the 
abdominal contents leads to a greater distension of the 
abdominal wall below this line of flexion than is the case 
in the erect position. Secondary folds may appear either 
above or below the one already mentioned, and in extreme 
flexion the furrow, usually very shallow, which connects 
the two furrows of the groin above the pubis, becomes 
emphasized and converted into a deep line. At the same 
time the furrow of the groin is deepened and the fore 
part of the iliac furrow rendered more distinct. The 
position of the afore-mentioned folds is often indicated on 
tlio surface of the abdomen, in the ordinary erect position, 
by delicate lines which merely affect the skin and do not in 
any way influence the surface contours. Consequent on the 
alteration in the form of the abdominal wall in the flexed 
position there is a disappearance of some of the most charac- 
teristic furrows, most notably the lateral abdominal furrows, 
wliiflj corrospond to tlio outer borders of the recti; these 
disiipprvar, and tlic rounded form of the flank becomes con- 
tinuous wiiii the general roundness of the front of the belly 



Contours of Abdominal I4''a/l 



85 



which lies below the best marked line of flexion. The most 
noticeable effects 01 extension of the trunk on the surface 
forms of the abdominal wall are a distinct flattening and 
stretching of that region, and a marked projection of the 




Fig. 50. 

surface corresponding to the outline of the lower thoracic 
margin due to the forward thrust of that portion of the chest- 
wall (Fig. 50 ; Pis., pp. 152, 158, 434). The anterior superior 
iliac spines are rendered more prominent, and the anterior 
part of the iliac furrow is obliterated, whilst its posterior part 



86 



Stemo-mastoid. - . ^ ^ 

Trapezius: - - . , "--v 
Pit o/mck:-- --,"■- 

Breast bone:- - , ^ ^ 
Deltoid. •■■' ~^_^ 

Pectoralis major, . _ 
Pit of stomach:- - . 
Biceps cubiti.- -,._ ^ 
Brachialis anticus. ^ ^ 
Rectus abdominis.. __^ 
External oblique. _ 
Brachialis anticus. . . 
Bicipital fascia. -- 
Int.condof hunu ■ ' 
Supinator longus:' 

Flexor carpi rad 
Ext.carp.rad.lont- 
Exts.of thumb./ _ 

Extensor com./ 

digitorum. 
Aponeurosis of 
ex t. oblique. ,- 

Poupartslig- ^ 

Sartorius. - '^ 
Rectus femoris. ' 
Vastus internus. 
Band of Richer. 
Rectus femoris. 
Vastus internus 
Internal condyle of femur 

Palctb. ■■■■"'__ 

Lig-^ patellae.' 
libia, subcut. surface. 
Gastrocnemius 




Sierno-mastoid. 
,.' -Trapezius. 

'" ^ ^'■'■Clavicle. 

Acromion process. 
Pectoralis major. 

' ,. Deltoid. 

'' Serratus mag. 
-^^ Brachialis ant 
-'' ,Biceps cubiti. 

Latissimus dor si, 
Triceps. 

Supinator long. 

.'Olecranon. 

--■...Anconeus. 

^ Ext.c-rad.long. 

E xt. carpi uln. 

-Ext. crad. brev. 

- -Gluteus medius. 

Extensor _ commun. 
digitorum. 

Extensors of thumb 

Gluteus maximus. 

-TrochanUr major. 

Rectus femoris. 

_ jBand of Richer. 

_ _ . _ Biceps cruris. 

_. Vastus externus. 

_ . . - . .-Rectus femoris. 

Ilio-tibial band. 

____ Patella. 

_ _ _ _ Biceps cruris. 

_.Head of fibula. 

Tubercle of tibia. 

- -Gastrocnemius. 

Peroneus longus. 

Tibialis anticus. 

Soleus. 

_Tendo A chillis. 



Peroneus brevis. 

Long extensor of great toe. 

' Long extensor of toes. 

- - External malleolus. 



Effect of Movements 87 

is somewhat deepened. Above, the flank is characterized 
by the deepening behind of the furrow which corresponds 
to the waist, and the flank itself is naturally more com- 
pressed and rounded behind, where it lies between the 
deepened furrows afore-mentioned, than in front, where it 
is continuous with the stretched tissues of the anterior 
abdominal wall. The lateral movements of the trunk 
naturally affect differently the forms of the flanks from or 
towards which the movement is made. The flank on the 
side opposite that towards which the body is bent is 
naturally stretched, and the furrows which define it above 
and below are obliterated, their places being taken by 
reliefs which correspond to the thoracic margin and the 
crest of the haunch-bone respectively. On the side to- 
wards which the movement takes place these furrows are 
deepened, and, owing to the compression of the tissues of 
the side of the body, the flank forms a prominent pad or 
elevation, the surface of which is traversed by numerous 
skin folds which are usually more distinct behind than in 
front (Pis., pp. 34, 44, 52, 72). 

The surface forms of the abdomen and flank are likewise 
affected by the movements of rotation, of which mention 
has been already made (p. 53) in connexion with the move- 
ments of the vertebral column. Their principal influence 
is to cause an obliquity of the longitudinal furrows, and to 
intensify the transverse furrows, namely those of the waist 
and crest of the haunch-bone, on the side toward which the 
body is twisted, whilst leading to their effacement on the 
side from which the body is turned (Pis., pp. 54, 86). ^ 

For the convenience of the reader, representations of 
the male and female figures in these lateral and rotatory 
movements have been placed side by side, in order not only 
to afford a comparison of the surface contours produced, 
but also to emphasize the characteristics of the two sexes. 
"Whereas, owing to the difference in the pelvic form, the 



88 Effect of Movements 

disfance between the iliac crest and costal margin is greater 
in the female, with a consequent increase in the length of 
the flank, it will be noted that the position of the waist, 
owing to the greater pelvic width, is more pronounced and 
placed higher in the female than in the male. Or, put in 
another way, the plates show how the longer flank in the 
female is disposed with a greater outward slope than is the 
case in the male. 

Combinations of these movements will necessarily be 
associated with modifications in the surface forms, but, 
bearing in mind the main points as they have been described 
in the simplest forms of movement, the student will be 
enabled to analyse more correctly the complex contours 
associated with combinations of these movements. 



CHAPTER y 

THE SHOULDER- GIRDLE AND THE MUSCLES WHICH 
INFLUENCE ITS MOVEMENTS 

We have next to study the manner in which the upper 
limb is connected with the trunk. This is effected in the 
skeleton by means of the shoulder- girdle, which is made 
up of two bones on either side, the collar-bone or clavicle, 
and the shoulder-blade or scapula. The striking difference 
between the arrangement of the bones of the shoulder and 
pelvic girdles has been already referred to in Chapter I, so 
that it is not necessary again to emphasize the character- 
istics peculiar to these portions of the skeleton. It will be 
sufficient to keep clearly in view the fact that the shoulder- 
girdle is particularly modified, in order to permit great 
freedom of movement between the upper limb and trunk. 

The collar-hone (Figs. 53, 54) may be compared to a rod 
bent into the form of the italic letter /. It possesses two 
extremities, the inner of which is enlarged and articulates 
with the upper end of the breast-bone, just above the 
junction of the first rib cartilage, to which the collar-bone is 
also firmly attached by ligament. The outer extremity is 
flattened from above downwards, and slightly expanded ; it 
is called the acromial end of the bone, because it articulates 
with the acromion process of the shoulder-blade. This end 
of the bone corresponds to the summit of the shoulder, and 
in the male lies at a slightly higher level than the inner 
or sternal end. The curves of the bone are so arranged 
that the part of the shaft near the breast-bone is bulged 
forward, whilst the outer half of the bone describes a curve, 



QQ Collar-bone 

the convexity of which is directed backwards. These curves 
impart a certain amount of spring to the bone, so that the 
shock of blows falling on the shoulder is reduced by the 




Fio. 51 A. Bones of the right upper limb, front view. 

a. ColIar-l>one (clavicli-). d. Humerus. g. Wrist-bones (carpus). 

b. Ureaiit-bone (sternum). e. Radius. h. Palm-bones (metacarpus). 

c. Shuulder-blade (gcapula). /. Ulna. i. Finger-boces (phalanges). 

.slight yielding of tlie curves, a condition which would 

not liold good had the bone been straight. 

TIni curves of tlui collar bone vary considerably in 



Collar-bone 



91 



different individuals. The variations are due in great part 
to the exercise or use to which the limb has been put. 
In persons who have to live by hard manual labour the 




Fig. 51 B. Bones of the right upper limb, back view. 

a. Collar-bone (clavicle). e. Eadius. h. Palm-bones (metacari us). 

c. Shoulder-blade (scapula). /. Ulna. i. Finger-bones (phalanges). 

d. Humerus. g. Wrist-bones (carpus). 



curves are more pronounced than in those whose occupation 
is sedentary, a difference which is to a greater or less extent 
also characteristic of the sexes. The curvatures of the bone 



g2 Collar-bone 

may therefore be regarded as affording some indication 
of the muscular development of the person to whom the 
bone belonged. As men are usually more muscular than 
women, the inference will be that a bone which displaj^s 
well-marked curves is that of a male. Differences in 
length may also be noted as having an important relation 
to the width of the shoulders. As the inner enlarged 
extremities of the collar-bones rest upon the upper extremity 
of the breast-bone, they are separated by a notch, the 
lower boundary of which is formed by the upper margin 
of the breast-bone. Passing across from one clavicle to the 




Fig. 52. Diagrammatic representation of the 
shoulder-girdle. 

a. First dorsal vertebra. d. Shoulder-blade (scapula). 

h. First rib. e. Collar-bone (clavicle). 

c. Breast-bone (sternum). /. Humenis (bone of upper arm). 

other, there is a strong band called the interclavicular 
ligament; this ligament smooths off the angles of the 
notch, which is thus converted into a rounded, well-marked 
depression between the extremities of the collar-bones on 
f'ithfT side and the breast-bone below (Fig. 55). It is 
this which causes the surface depression known as the pit 
of the neck, the distinctness of which is further increased 
by the attachment of one of the neck muscles, to which 
n'f(!rence will be made in a future chapter. 

From what has been stated regarding the collar-bone 
and its articulations it will be easy to understand how it 
acts as a prop or fulcrum on which the shoulder-blade 
moves. Thi.s action of the bone may be readily demon- 



4 



Shoulder-blade 93 

strated if we compare its position when the limb is thrown 
forward and when it is drawn back. In the former case 
the collar-bone is pulled forward from the chest-wall, whilst 
in the latter action the bone is brought into closer relation 
with ib. Fig. 56 represents, in^ diagrammatic way, these 
actions. 

The sTioulder-hlade or scapula (Figs. 57, 58, 59) is a thin 
plate-like bone of triangular form, with certain outstanding 
processes. It is placed on the upper and posterior aspect of 
the chest-wall, overlying the second to the seventh ribs 
inclusive. In the upright position with the arms by the side, 
the interval between the two blade-bones usually corresponds 
to the width of the neck. As a triangle, the bone possesses 





Right collar-bone (clavicle). 
Fig 53. As seen from the front. Fig. 54. As seen from above. 

a. Shaft. c. Acromial end, with articular surface 

h. Sternal end. , for acromion process of scapula. 

three sides and three angles. The borders are described as 
inner, outer, and superior. It may be well here to add some 
explanation of the use of these terms in anatomy. The body 
being symmetrical on the two sides, we can divide it by 
an imaginary plane, which we term the mesial plane. As 
this plane bisects the trunk in front and behind, it corre- 
sponds to the middle lines of these regions. In comparing 
the position of one structure with another in relation to 
this mesial plane we describe as internal that which lies 
closer to it, whilst that which is placed wider from it is 
accounted external ; thus the ear is external in position 
to the eye. 

When therefore we examine the shoulder-blade in 
position on the back of the chest-wall, that border which 



94 



Spt-f of yil cervical vertebra 
Trapezim 

/lircmion process 

spine of stapula 

Dellcid - 
Infraspinatus 

Teres majcr . 
Rlionib maj . 
Thoracic vail 

Lal.dorsi 

Triceps. 

long head 

Biceps 

Triceps 

'tendon -■ 

'in head . 
Brack ant . . 

Olecranon 
y4iic0nens..\i^ 
fiictp/as • 
Prtm r ter 
r.xt Miq 
tlifi< trtil 
roU fnp 
that iptne 
Putm long 
1 1 r,trp rad 

medium 
it carp.uln. 

Jrotttantrr 

ma)0\ 

Clnltui 

llto-ttbtal 
b*nd 

liutp\ 
(rum 

yaitHi fit 

^mtt ffmttii 



'.. Trapczii 

. yicroviion proces 

— Dc/fou 

lirocliinlis ■iiitict 
: Biceps ciibii 
: \ Siip./oiigt 




■External obliqt 

■Lumbar aponeuros 

Iliac crei 

Posterior superior iliac spti 
Gluteus inedi 

Trochanter inaj 
Gluteus maxim 

Ilio-tibial bai 

Semt-teiidiuos 

Biceps crm 

yaslus extern 




^ 



Shoulder-blade 



95 



lies nearest the middle line is called the internal, that 
margin which lies in relation to the back of the armpit is 
called the external, and the third side of the triangle, 
which is placed above, is called the upper or superior 
border. In like manner the angles of the bone are described 
as external and internal ; the latter, two in number, are 
placed at the upper and lower ends of the internal border 
of the bone, and are distinguished the one from the other 
as the superior internal and inferior internal angles of the 
bone ; more frequently, however, these are spoken of as 
the superior and inferior angles. Of the borders the 




Fig. 55. Showing articulation of the collar-bones (clavicles) with 
the breast-bone (sternum). 



a Collar-bones (clavicles). 

h. Sternal ends of collar-bones. 

c. Placed on the first and second ribs. 

d. The tipper piece of the breast-bone 

(manubrium sterni). 
/. Rib cartilages. 



g. Placed over the body of the first dorsal 
vertebra, lies in the interval between 
the sternal ends of the collar-bones, 
a space which corresponds to the 
surface depression at the root of the 
neck, called the pit of the neck. 



most important, from our standpoint, are the internal and 
external. The latter can readily be felt, covered though it is 
by muscle, by firmly grasping the tissues which lie behind 
the armpit. The inner border, overlaid by much thinner 
muscles, is readily seen, particularly if we move the arm 
about so as to rotate the shoulder-blade. Of the angles, the 
superior and inferior are easily distinguishable, particularly 
the latter, which can be observed to advance across the chest- 
wall when we raise the arm over the head. The external 
angle, which furnishes the shallow socket for the lodgement 
of the head of the humerus, is obscured by the structures 



g6 Shoulder-blade 

around the shoulder-joint. It will be described at greater 
length when the anatomy of that joint is considered. 

Arising from the posterior surface of the shoulder- 
blade is the process called the sj^im. This is somewhat 
triangular in form. It is attached by one of its borders 
to the blade-bone, the posterior surface of which it 
thus divides into two unequal fossae, called respectively 
the supra- and infra-spinous fossae, according as they 
lie above or below the spine which separates them. The 
remaining two sides of the spine form free borders, that 
is to say, they are not attached by osseous union to any 
other parts of the bone ; one, the longest or posterior 




Fig. 56. On the left side of the figure the girdle is shown pulled 
back, on the right side drawn forward. 

a. Collar-bone (clavicle). c. Breast-bonQ. e. First rib. 

6. Shoulder-blade (scapula). d. First dorsal vertebra. 

border, is superficial throughout its entire extent, and 
forms an important factor in the modelling of the 
surface contours over it. The external border is short 
and curved, connecting the external extremities of the 
attached and the posterior borders. The plane of this 
triangular spinous process is oblique to the plane of the 
blade-bone in an upward direction, a fact which is best 
displayed on making a section of the bone. Its upper 
surface forms part of the floor of the supra-spinous fossa, its 
under surface part of the infra-spinous fossa. 

The inner angle of this spine, formed by the convergence 
of tin; posterior and attached borders, corresponds to the 
point of junction of the upper with the middle third of the 



Shoulder-blade 



97 



internal border of the blade-bone. There are two external 
angles, one anterior, which corresponds to the outer end of 
the attached border, the other posterior, which is formed by 
the fusion of the external with the posterior border. At 
this point the spine becomes continuous with a process called 
the acromion process, which is carried upwards and outwards 
for some distance, in line with the posterior border of the 




The right shoulder-blade (scapula). 
Fig. 57. Back view. Fig. 58. External view. Fig. 59. Front view. 



a. Glenoid fossa, for head of humerus. 
6. Spine. 

c. Acromion process. 

d. Facet for outer end of collar-bone. 

e. Coracoid process. 
/. Superior angle. 



g. Inferior angle. 
h. External or axillary border. 
i. Internal or vertebral border. 
k. Superior border. 
I. Supra-spinous fossa. 
m. Infra-spinous fossa. 



n. Ventral or anterior surface. 

spine. It then turns somewhat suddenly forwards, and 
becomes compressed and flattened, so that its surfaces are 
directed upwards and downwards. It arches over the 
shoulder-joint, and is furnished on its inner border near its 
extremity with a small facet, by means of which it articulates 
with the outer end of the collar-bone. This process is of 
great importance in relation to the surface contours, as it 
forms the summit of the shoulder, and is superficial 

THOMSON H 



98 



— Ext.cat^i uliiiiris 



Sptne of I 'II (.cnncal vertebra 
Traptstiti .. 
/Icromtjn process ■■., 
Spmt of scapula ^ 

Dtltmd ._ ■■••... 

/n/ra-sptnatus ,'"•• 



...Triceps, outer head. 

Triceps, long head. 

Deltoid. 

..^1 crotnion process. 

Trapezius 

spine of sea pill a- 

Teres major. 

Teres minor. 

■Infra-spinatus 

Rlumihotdcus major. 




Brachialti ant .. 
Exierual oblique 

OUcraiioii 

Int. condyle 

liuipital/ai .. 

Ljumbar 

aponrHroiii .. 
ProH rad trr ■■■ 
Piilmarti long . 

Iliac tretl 

J-ltxor (orfti 
ulnam . . . 

/'oit.tup list ■ 

Fl cart rod ■ ■ 
Cinteui nitdiui 



I rc^hiiHlrr 'tuiinr,. 

Cimltni max 
tli0-ltb^al band 



Lumbar aponeurosis. 
Iliac crest. 

■Posterior superior iliac spine. 

-Gluteus medius. 

Gluteus tnaximus. 

Tensor fasciae fetHoris. 
Trochanter major. 

Jlio-tibial band. 



Shoulder-blade 



99 



throughout. These details, though somewhat tedious, are 
necessary, as without a knowledge of the shape of this bone 
it .will be difficult to understand its relation to the surround- 
ing muscles and to the surface. 

Another process of hook-like form, called the coracoid 
process, springs from the upper border of the blade-bone, 
close to the external angle. This is important only as 
affording attachment to muscles 
and ligaments, and is not a deter- 
minant of surface form. 

The surface of the blade-bone, 
opposite that to which the spine 
is attached, is hollowed out so as 
to form a shallow fossa in which 
fleshy muscles are lodged. This 
surface is directed towards the 
chest-wall, and lies in relation to 
the outer surfaces of the ribs, 
being separated from them by 
sheets of intervening muscles. As 
has been said, the collar-bone 
articulates with the acromion 
process of the shoulder-blade. The 
joint itself is small and weak, but 
is very much strengthened by 
powerful ligaments which pass 
between the collar-bone and the 
coracoid process. 

By the articulation of these bones an angle is formed, 
which is occupied in great part by the rounded form of 
the upper part of the chest-wall. The interval between the 
girdle and the thoracic wall is occupied by the vessels, 
nerves, and muscles of the upper limb. By means of 
the above joint, the angle between the collar-bone and the 
plane of the blade-bone can be modified so as to adapt 

H 2 




Fig. 6o. The outer side of 
the shoulder-blade (scapula). 

a. Glenoid fossa, for head of 

humerus. 
h. Spine. 

c. Acromion process. 
e. Coracoid process. 
g. Inferior angle. 
h. External or axillary border. 
I. Supra-spinous fossa. 
m. Infra-spinous fossa. 
71. Ventral or anterior surface. 



loo Shoulder-girdle 

it to the form of the chest-wall. When the shoulders 
are drawn back the angle is opened out ; when the arms are 
thrown forward the angle is diminished (Fig. 6i). A slight 
amount of rotation of the blade-bone on the extremity of the 
collar-bone may also take place at this articulation. The 
continuity of the clavicle with the acromion can easily be 
demonstrated on the living ; if the finger be placed on the 
inner end of the collar-bone, then the outline of the bone 
can readily be traced towards the shoulder to the point 
of its articulation with the acromion ; this is usually 
recognized as a slight elevation. Passing round the summit 
of the shoulder, the upper surface of the acromion can be 




Fig. 6i. On the left side of the figure tlie girdle is shown pulled 
back, on the right side drawn forward. 

a. Collar-bone (clavicle). c. Breast-bone. e. First rib. 

h. Shoulder-blade (scapula). d. First dorsal vertebra. 

distinctly felt, and, if it be followed backward, the finger 
will pass along the posterior border of the spine, until the 
point is reached where that process blends with the in- 
ternal margin of the blade-bone, a point which is still 
further emphasized in the living, owing to the arrangement 
of the muscles around it. 

The only articulation which the blade-bone has with the 
trunk is indirectly through the collar-bone, by means of 
the union of the latter with the breast-bone. It is at 
this joint, therefore, that many of the movements take 
placft which influence the position of the shoulder-blade. 

Thf? movements possible at this joint (sterno-clavicular 
a» It is called) when reduced to their simplest form are 



Shoulder-girdle loi 

those in an upward, downward, forward, and backward 
direction, together with a slight degree of rotation of the 
collar-bone on its own axis. These of course may be 
variously combined. As has been seen, certain movements 
take place at the acromio-clavicular joint, so that the 
movements of the blade-bone are further complicated by 
the addition of those which are effected at the sterno- 
clavicular articulation. 

But, whilst the shoulder-blade is only thus slightly con- 
nected with the osseous framework of the chest, it is very 
efficiently supported and held in position by the many 
muscles with which it is connected, and these react on the 
surface form according as they are strongly developed 
or not. 

In man we usually find the outer end of the collar-bone 
lying at a somewhat higher level than the inner end. In 
woman the outer end of the bone lies either about the same 
level as the inner end, or somewhat lower. In other words, 
in the male the collar-bones tend to slope outwards and 
upwards ; in the female, outwards and downwards. This is 
owing to the different form of the thorax in the two 
sexes. The smaller and narrower chest of the female affords 
the girdle less support than in man, in whom the larger 
thorax furnishes a wider surface on which the girdle may 
rest. But, independently of the form of the framework of 
the chest, there are other factors which must be taken 
into account ; these are the muscles. It often happens that 
a person with sloping shoulders is recommended to indulge 
in some form of gymnastic exercise to expand his chest. 
After the age of twenty-fiv.e, when all the bones are fully 
ossified and the figure set, any form of exercise will have 
but little influence on the form of the thorax, except that 
it stimulates a more healthy respiration. Yet we cannot 
but adn^it the effect which the exercise has had on the man, 
for he appears now with braced-up figure and square 



102 



Shoulder-girdle 



shoulders. The increase in breadth of the chest is not due 
to any marked increase in the capacity or form of the chest- 
wall, but is due almost entirely to the increase in size of 
the muscles, brought about by exercise. As has been shown, 
some of these muscles lie between the blade-bone and the 
chest-wall, and one can readily understand how any in- 
crease in the thickness of these layers will tend to push 
upwards and outwards the blade-bone from the chest-wall, 
and so impart to the shoulders that squareness which is so 
desirable in the male figure. 

In regard to the relative proportions of these bones to 
others, we find that the collar-bone is usually about the 
same length as the osseous part of the breast-bone, or about 
half the length of the bone of the upper arm. The length 
of the internal border of the shoulder-blade very nearly 
approximates to that of the collar-bone. These measure- 
ments are very liable to vary, and must not be taken as 
affecting any scientific accuracy; they are merely put 
forward as aids to assist the draughtsman in apportioning 
approximately the lengths to these different bones. 

Before passing to the consideration of the muscles which 
move the upper limb on the trunk, it will be necessary 
to enter into a short explanation of the mode in which 
muscles act. Taking the simple case where two long bones 
are united by a joint which permits of a hinge-like move- 
ment, it will be apparent that any muscle attached to the 
upper bone and passing down over the joint, either in 
front of, or behind it, to be inserted into the lower bone, 
will, when it contracts, effect a movement of the low^er 
bono on the upper. If the muscle passes in front of the 
joint, the limb will be bent or flexed ; if it passes behind 
the joint, the limb will be straightened or extended. Such 
muscles are called direct flexors or extensors. 

lint it not nnfrequently happens that a muscle which 
takes origin from tlio upper bone is not inserted into the 



Action of Muscles 103 

bone immediately below, but passes over that bone to be 
inserted into one beyond. In this case the muscle passes 
over more than one articulation. All the intervening joints 
may be influenced by the contraction of such a muscle, 
but as the action of this muscle is not brought to bear 
directly on the intermediate bone it has been described as 
possessing an indirect action. 

To take the case with which we are immediately con- 
cerned. A number of muscles pass from the trunk to the 
bones of the shoulder-girdle. These have a direct influence 
on the movements of the bones of the girdle, but there are 
others which, arising from the trunk, are not attached to 
the bones of the girdle, but pass to be inserted into the bone 
of the upper arm, which is connected with the shoulder- 
girdle by the shoulder-joint. These muscles act primarily 
upon the bone of the upper arm, moving it at the shoulder- 
joint, but they also secondarily affect the movements of the 
girdle through its connexion with the bone of the upper 
arm. This is the indirect action of these muscles, and they 
are therefore described as acting indirectly on the move- 
ments of the girdle in contradistinction to those which act 
directly upon it. 

Arranging the muscles according to their action, it will 
be most convenient to take up the consideration of that 
group which acts directly on the girdle, namely, those 
which arise from the trunk and are inserted into the bones 
of the girdle. It will not be necessary to describe them 
all, for some have no influence on the surface form, and 
may for present purposes be disregarded. 

The muscles with which we are particularly concerned 
are the trapezius, the rhomboids, the levator anguli scapulae, 
the serratus magnus, and the pectoralis minor. Be it under- 
stood that these muscles are symmetrical on' the two sides 
of the body. There is a pair of each, one of each psfir being 
assigned to opposite sides of the trunk. 



I04 




Pit of neck. 
Stenw-mastoid.- . 

Clavicle.-^ "^ 
Subcutaneous Part of breast bone. , ^ ^ - 

DcUo'ui.Sf" 
Pectoralis major. ; - 
Biceps ciibiti.^S^ 
Styloid process of ulna. I- S^ 
Extensor carpi nliuiris.^y . 
Flexor carpi nlnaris.,^ '-« 
Flexor, offngers.,^'--- 
Fle.xor carpi radialis. , ~--. 
Posterior border of ulna.^^-^. 
Pronator radii teres., ~ - 
Drackialis anticus., '- 
Bicipital fascia^, [- 
Internal condyle of humerus.^ ^ - 
Olecranon process of ulna.^ "■ 
Rectus ftnoris taidon.^^ 
Vastus internus.. 

Patella /-^: 

Sattd of Richer. /-J--c:y 

J^at...- li'^^^'^^ 

Ligamentum patellae 

Tendon of Sar tortus 
■"* " '• Scmi-tendy 
Tibialis anticus. 
Tibia, subcutaneous surf. 
Castroc.inner head.- 
Soleus. . , 
I^ong flexor of toes. 
Tendo A chillis. 
I nt.ann. ligament. 
Internal malleolus: 

/Inn tig of ankle. 
Tendon of 
Tib-ant.- 
Tib.poit 



Abductof gt.toe 



^^Mlio-tib.bd. "i 
\ ''Semi-memb.2-.tend. 

\^ Tendon of Biceps. 
.. ~ 'Head of Fibula . 

'Gastrocout.head. 

Soleus. 
" 'Peroneus longus. 
' 'Long extensor of toes. 
' ' " Peroneus brevis. 
' " " -Tibialis anticus. 
. . -Fxtcrnal malleolus. 

Tendo A chillis. 

■Extci-nal annular lig. 
' "Os calcis. 
'Short extensor of toes. 
'^PeroJteus brevis. 



'. Peroneus tertius. 

Abductor of little toe. 



2\ An tenor tuperior iliac spine. 
*l'li>artoriut. 



Sterno-mastoid.. 

-Spine of VII cervical vertebra. 
Clavicle. 

Trapezius. 
I Acromion process of scapula. 
Infraspinatus y 



major, 
mboid. major 
atissrmus dor si 
■alis^najor 
v.fibres. 
biceps Lhd. 
out. head 

1 

2 

- 3 

4 



. "9 
~ 10 
^11 

"-12! 

~~~-14 

\ \ ;~i' 

'\ Gluteus maximus 
\ Trochanter major. 
Rectus femoris. 
Vastus externus. 
Biceps cruris, short and long head. 

Pectoralis tnajor, sternal fibres. 

Biceps cubiti and Brackialis anticus. 

Triceps tendon. 

Serratus magnus. 

Olecranon process of ulna. 

External condyle of liumerus. 

Anconeus. 

Supinator longus. 

Extensor carpi radialis longior. 

External oblique. 1' 
Extensor communis dtgttoru?n. 1 
Extensor carpi radialis brevior. II 
Gluteus medius. 1« 
Tensor fasciae femoris. 1^ 
Extensors of thumb. 1. 
Extensor carpi ulnar is. 1' 

Extensor secundi inter nodii pollicis. 1' 

Pit of stomach, l! 

Triceps, innef and long bead. 1 

Rectus abdominis, tendinous intersections.. 2 








wmdkmim^ 



Trapezius 105 

Unfortunately there is no English equivalent for these 
technical names, so that the student has no other alternative 
than to acquire a familiarity with these anatomical terms. 

The trapezius (Fig. 62), so called from the four-sided 
figure which the muscles of opposite sides form, has been 
compared, when we consider the muscles of both sides 
together, to a tippet hanging over the shoulders, the tip 
of which reaches to about the level of the spine of the 
last thoracic vertebra. In order to render this description 
intelligible, it is necessary to supplement it by supposing 
that the muscles extend upwards along the back and sides 
of the neck to the skull, somewhat in the fashion of a high 
collar, the peak of which reaches the back of the head. 

The two muscles take origin from the middle line, ex- 
tending above as high as the back of the skull or occiput, 
on either side of which they are attached for a variable 
distance to a rough ridge which is called the superior 
curved line of the occipital bone ; and reaching as low down 
as the level of the spine of the last thoracic vertebra. 
In the neck the muscles arise from a medium ligament, 
which extends from the occiput superiorly to the spine of 
the seventh neck vertebra, or the vertebra prominens, 
inferiorly. Below this level the muscles are attached to 
the tip of the spine of the seventh neck vertebra, to the 
spines of all the thoracic vertebrae, and to the ligaments 
which connect these spines together. 

From this wide attachment the fibres converge to be 
inserted into the outer third or fourth of the posterior 
border of the collar-bone in front, and along the entire 
upper border of the acromion process and spine of the 
shoulder-blade at the side and behind. This insertion 
involves a considerable alteration in the direction of the 
fibres of the different parts of the muscle ; thus the fibres 
which arise from the occiput and neck pass downwards, 
outwards, and forwards to the collar-bone and acromion, 



1 06 Trapezius 

whilst those which spring from the lower thoracic spines 
ascend upwards and outwards to the root of the spine 
of the shoulder-blade. The fibres which arise from the 
intermediate attachments of the muscle pass outwards 
with varying degrees of obliquity, whilst those which spring 
from the upper two dorsal spines are nearly horizontal in 
direction when the limb is at rest by the side of the 
trunk (Pis., pp. 34, no, 138). 

The muscle is attached to these points and surfaces by 
means of tendinous fibres, which are usually short ; but in 
some situations they are longer, and give rise to alterations 
in the surface forms dependent on this muscle, for where 
the tendinous fibres are long they are represented on the 
surface by flattened depressions in contrast with the pro- 
minences produced by the contraction of the fleshy fibres. 

The tendinous fibres are long at the origin of the muscle 
in the lower region of the neck and upper part of the 
thorax ; they reach their maximum length about the level 
of the spine of the vertebra prominens (seventh neck 
vertebra) ; a lozenge-shaped figure is thus formed by the 
muscles of opposite sides, the inferior angle of which 
reaches as low as the third thoracic spine, whilst above 
it gradually tapers towards the occiput. On a level with 
the external angles of this area is the projection formed 
by the spine of the seventh cervical vertebra in the middle 
line. During the powerful contraction of the muscles this 
area corresponds to a surface depression, in the centre of 
which the projection caused by the spine of the seventh 
cervical vertebra is readily recognized (Pis., pp. 94, 98, 
no, 138). 

At the lowest point of origin of the muscle from the last 
two or three dorsal spines the tendinous fibres form a small 
triangular aponeurosis. This, combined with that of the 
opposite side, forms a diamond-shaped surface, which, when 
the muscles are powerfully contracted, corresponds to a 



Rhomboids 107 

depression on the surface of the back of somewhat similar 
shape, though less apparent than the above (Pis., pp. 50, 182). 
A third tendinous area is noticeable over the' point where 
the spine of the shoulder-blade becomes blended with the 
internal border of that bone. As the parts of the muscle 
around this are thrown into relief during contraction, there 
is a surface depression in correspondence with it, but the 
position of the depression varies with the movements of 
the blade-bones (Pis., pp. 34, 44, 54, 94, 98, no, 126, 138, 
182). 

The entire muscle is superficial ; that is to say, it is merely 
covered by the skin and the superficial fatty layer which 
lies beneath the skin. According to the thickness of this 
fatty layer the sharpness of the surface forms dependent 
on the muscle will vary, being obscured in those in whom 
there is much fat. The surface forms also depend on the 
development of the muscles themselves. 

These muscles overlie deeper layers of muscles, and so 
they themselves are influenced by the form of the structures 
on which they rest. On either side of the middle line 
the rounded form of the back is not due to the trapezii, 
which here constitute a comparatively thin layer, but 
depends on the fullness of the erectores spinae group upon 
which they lie (Pis., pp. 34, 38, 50, 94, 98). 

Beneath the trapezius there are three muscles attached 
to the internal border of the blade-bone. These are the 
two r^o?726o2c?5 and the elevator of the angle of the scapula. 
For our purpose we may consider the two rhomboids as 
forming one muscular sheet. This is attached along the 
middle line, extending as high as the lower half of the 
median ligament of the neck, and passing downwards to 
be connected with the spine of the seventh neck vertebra 
and the spines of the first five thoracic vertebrae. The 
muscle lies higher at its origin than at its insertion, so 
that its fibres are directed downwards and outwards towards 



io8 



Rhomboids 



their insertion into the inner border of the shoulder-blade, 
where their attachment extends from the root of the spine 
down to the 'inferior angle (Fig. 62). 

These muscles, although covered by the trapezius, with 
the exception of a small portion below close to the inferior 




Fio. 62. View of the muscles attached to the shoulder-blade. The 
trapezius has been cut away on the left side of the figure. 



a. Trapezius musclo. 

b. Rhomboid. 

c. Elevator of the angle of the scapula 

(levator anpuli scapulae). 

d. Splenius muscle. 

«. Complexus muscle. 



/. Sterno-mastoid muscle. 

g. Infra-spinous fossa on back of scapula. 

h. Acromion process of scapula. 

*. Spine of scapula. 

3. Collar-bone (clavicle). 

k. Humerus. 



angle of the blade-bone, exercise a considerable influence 
on the surface contours, as, in repose, as well as during con- 
traction, they form a somewhat broad and oblique elevation 
which accentuates the relief of the trapezius muscles which 
overlie them (Pl.s., pp. 34, 44, 94^ ga no). The elevator of the 



Action of Trapezius . 109 

upper angle of the scapula (levator anguli scapulae) arises from 
the transverse processes of the higher neck vertebrae and is 
inserted into the inner border of the blade-bone above the 
level of the spine. It is merely mentioned here as it assists 
in giving the rounded form to the neck and this part of 
the back. The greater part of the muscle is covered by the 
trapezius. 

The action of these several muscles may now be described. 
As will be seen from a study of the direction of its .fibres, 
the upper and lower portions of the trapezius may antagonize 
one another. The upper or neck part of the muscle 
may act in one of two ways, according to which of its 
extremities is fixed. If the shoulder-girdle be rendered 
immovable, and both muscles act at the same time, the 
head will be extended, that is, thrown back (PL, p. 44). 
If one muscle alone be brought into play the head will^ 
be drawn to the same side, and rotated slightly away from 
the side on which the muscle is contracting. If, on the 
other hand, the head and neck be fixed, the upper fibres of 
the muscle will raise the shoulder-girdle, while the inter- 
mediate fibres will also assist in elevating the point of the 
shoulder (Pis., pp. 94, 98, 158, 162). If the lower fibres be alone 
called into action they will depress the shoulder-blade, and 
thus draw down the shoulder. The intermediate fibres also 
act in drawing the blade-bones closer to the middle line, 
as in the act of pulling back the shoulders (Pis., pp. no, 138), 
and the entire muscle, acting at one and the same time, fixes 
the shoulder-blade, and thus furnishes a firm base of support 
from which the limb may act (see also Pis., pp. 38, 44, 50, 
52, 54, 94, 98, no, 126, 158, 162, 382). 

It is needless to say that these movements are the result 
of a combination of the action of manj^ other muscles, but 
for present purposes it is best to simplify the description 
as much as possible. The rotatory movements of the 
scapula will be described later. 



110 




Serratiis magnus 



III 



The rhomboids elevate the blade-bone and draw it nearer 
the middle line. The levator anguli scapulae, as its name 
implies, raises the upper angle of the bone. 

The serratus magnus muscle is a broad, somewhat fan- 
shaped sheet of muscular fibre, and has an extensive origin 
from the side of the chest-wall. Passing backwards it is 
closely applied to the chest- wall, and lies between it and 
the deep surface of the blade-bone, to the inner border 
of which it is attached. The position of this muscle is 
difficult to understand : a diagram may help to explain it. 
Fig. 63 represents a section across the chest-cavity ; 
the shoulder-blades are seen on either side and behind, 




Fig. 63. Diagrammatic section across the chest to show the relations 
of tha great ssrratus muscle. 



a. Head of humerus. 
h. A dorsal vertebra, 
c. Ribs in section. 



d. Breast-bone. 

e. Shoulder-blade. 

/. Serratus magnus muscle. 



and the muscle is represented in section, arising from 
the side of the chest-wall, rather towards the front, and 
passing back between the chest- wall and shoulder-blade 
to be attached to the inner border of that bone. Only 
a small portion of the muscle is superficial, as it is in great 
part covered by other muscles and by the blade-bone ; but 
the part which is superficial has a most important influence 
on the surface forms, and corresponds to that row of finger- 
like elevations on the side of the chest-wall with which the 
student is familiar in the model when the arm is raised 
(Pis., pp. 38, 62, 72, 86, 122, 126, 148, 152, 158); they are 
well shown on the figure of the Gladiator. These elevations 



112 



Serrahis magnus 



correspond to the points of origin of the muscle, and it will 
be necessary to describe them (see Figs. 64, 65). The muscle 
arises by eight or nine fleshy slips from the outer surface of 
the eight upper ribs. The upper fibres may be disregarded. 
The fibres from the lowest five or six slips of origin converge 
in a fan-like shape to be inserted in the lower angle of 
the inner border of the blade-bone, forming a well-marked 
fleshy prominence which, though it is not superficial, yet 




Fig. 64. View to show the 
Bcrratub magnus muscle with the 
shoulder-blade in its natural 
position. 



Fig. 65. The same, with the 
shoulder-blade turned away from 
the chest-wall in order to show the 
insertion of the muscle into the 
anterior aspect of the inner or 
vertebral border of the bone. 



n. Shouldc-r-blade. 

b. Glenoid fossa ior head of humerus. 



c. Coracoid process. 

d. Acromion process. 



infhiences to a marked degree the surface contour (Pis., pp. 
34, 44, 122). The muscle which covers it, and which will 
bo presently described, forms a relatively thin layer over it. 
The lower and anterior part of the serratus muscle is, however, 
superficial, and it is here that its influence on the surface 
coni(jiirs is most readily recognized. This part of the muscle 



Serrqtus magnus 



113 




comprises the lowest four slips which arise from the surfaces 
of the fifth, sixth, seventh, and eighth ribs. These slips 
consist of pointed, finger-like, fleshy processes, caUed digita- 
tions, and, owing to the fact that they are placed between 
corresponding slips of origin of the external oblique muscle 
of the abdomen, they are 
said to interdigitate with 
these attachments of the 
latter muscle, just as we 
can thrust the fingers of 
one hand between the 
fingers of the other. 

It is this arrangement 
which gives rise to the 
zigzag furrow which is so 
characteristic a feature of 
the lower and lateral part 
of the chest-wall in violent 
action of these muscles. 
The general direction of 
the furrow so produced 
corresponds to a gently 
curved line, with the con- 
vexity directed down- 
wards, drawn from the 
nipple above towards the 
posterior end of the crest 
of the haunch-bone below 
(Pis., pp. 86, 152, 158). 

The furrow is obliterated for a short distance below the 
nipple by the fleshy mass of the great pectoral muscle ; 
inferiorly ^nd posteriorly it fades away, where it joins 
the broad shallow furrow of the waist, and where it is 
overlapped by the lower fibres of the latissimus dorsi. The 
two muscles which have just been mentioned, the latis- 



FiG. 66. A view to show the struc- 
tures which underlie the deltoid and 
great pectoral muscles, the outlines of 
which are represented in dotted lines. 
The separation of the clavicular fibres 
from the sternal fibres of the great 
pectoral is also shown by a dotted 
line. 

a. Collar-bone (clavicle). 

b. Breast-bone (sternum). 

c. Acromion process of scapula. 

d. Coracoid process of scapula. 

e. Peotoralis minor muscle. 
/. Coraco-bracbialis muscle. 

g. Short head of biceps muscle. 
ti. Long head of biceps muscle. 
k. Humerus. 



114 Action of Serrahis magnus 

siraus dorsi and the pectoralis major, will be described 
in the next group. It has been necessary to anticipate 
here in referring to them. The higher fibres of the serratus 
magnus are not as a rule exposed, except when we raise 
the arm over the back of the head, in which action the surface 
of the chest-wall in the hollow of the armpit corresponds to 
these fibres (Pis., pp. 152, 158). 

The muscle assists in keeping the blade-bone closely 
applied to the chest-wall, and during contraction draws it 
forward as a whole (Pis., pp. 44, no, 122, 126, 138). It is 
brought into play in the act of pushing, and is the chief 
muscle by which the thrusting movement in fencing is 
effected. It can also bring about rotation of the shoulder- 
blade, but the description of this movement is for the time 
delayed. 

The pectoralis minor muscle (Fig. 66) is not important 
as a modifying influence on the surface forms, for it is 
covered as a rule by the great pectoral, and it is only in ex- 
ceptional positions of the limb that we can trace directly 
its form on the surface. It takes origin from the front 
of the chest- wall under cover of the great pectoral ; its fibres 
arise from the third, fourth, and fifth ribs, just where these 
unite with their rib cartilages, and passing upwards and 
outwards it is inserted by means of a pointed tendon into 
the hook-like coracoid process of the shoulder-blade. Under- 
lying, as it does, the great pectoral, it imparts a fullness 
to the upper fleshy part of the chest, and when the arm 
is raised upright a small part of its lower border becomes 
superficial. This does not give rise to any distinct eleva- 
tion of the surface, but helps to impart the rounded form to 
the floshy fold which bounds the hollow of the armpit in 
front (Pis., pp. 152, 158). During contraction the muscle 
depresses the shoulder and assists in drawing it forward. 

It is by the combined action of certain of these muscles 
which have just boon described that the movements of 



Rotation of Scapula 



115 



rotation of the scapula are effected. The manner of their 
action can best be explained by the aid of diagrams. 

Fig. 67 represents in a schematic way the combined 
action of the trapezius behind and the serratus magnus in 
front. The lower fibres of the trapezius tend to pull 
downwards and backwards the upper angle of the blade- 
bone ; the serratus draws downwards and forwards the 
inferior angle ; the result is a rotation of the bone by which 
the lower angle is advanced and the upper angle pulled 
back in the directions represented by the arrows in the 





Figs. 67 and 68. Diagrams to show how rotation of the scapula is 

efifected. 



a, Pectoralis minor muscle. 
6. Rhomboideus muscle. 

The combined action of these muscles 

will cause rotation in the direction 

indicated by tho arrows, 
c. The fibres of serratus magnus attached 

to lower angle of shoulder-blade. 



d The lower fibres of trapezius passing 
up over root of spine. 
In combination these portions of 
the muscles will cause the bone 
to rotate in the direction of the 
arrows. 



diagram. Fig. 63 shows rotation in the opposite direction. 
The rhomboids and elevator of the angle, attached to the 
inner border of the blade-bone, draw the lower angle 
upwards and nearer the middle line, whilst the pectoralis 
minor, inserted near the external angle, drags down- 
wards and forwards that part of the bone, the combination 
of the two actions being a rotatory movement in a direction 
opposite to that above described. This difference is indi- 
cated by the direction in which the arrows point. 

I 2 



ii6 



Humerus 



Before describing those muscles which have an indirect 
influence on the movements of the shoulder-girdle through 



\^^ a 




k I 




Rij(ht humerus. 



Via. 69. Front view. Fig. 70. Outer side. Fig. 71. Back view. 



a. Hend. 

b. Greater tuberosity. 

c. Ix^ggcr tuberosity, 

d. Bicipital (jroovo. 

f.. \)n\\i>\<{ impression wlioro deltoid 

muscle is inserted. 
/. Internal condyle. 
y. External condyle. 



h. Capitellum for articulation with head 

of radius. 
t. Trochlear surface for articulation 

with ulna. 
j. External condyloid ridge. 
k. Internal condyloid ridge. 

These ridges afford attachment to the 

external and internal intermuscular 

septa respectively. 



Ihoir attachment to the bone of the upper arm, it will be 
necessary to say something about that bone, and also to 



Humerus ' 117 

give some account of the shoulder-joint. The bone of 
the upper arm is called the humerus. It is the first example, 
as yet met with, of a long bone. As has been seen, the 
long bones occur only in the limbs and serve as the levers 
through which the power is transmitted. As the bones 
of the upper limb are not concerned in supporting the 
trunk, they are smaller and not so stout as the bones 
of the lower limb which have to sustain the body weight. 
The long bones have many characters in common ; they 
are usually described as consisting of a shaft and two 
extremities. Of the latter, the upper is usually called the 
head. To this rule there is an exception in the case of 
the ulna, the inner bone of the fore-arm, the lower end 
of which is named the head. This term, though usually 
applied to the upper extremity of a long bone, is not so 
employed unless that end of the bone displays a rounded 
appearance — thus we speak of the head of the humerus, the 
head of the femur, the head of the radius, but we do not 
so describe the upper end of the tibia. Both ends of 
a long bone are provided with articular surfaces, whilst 
the shaft affords attachment for the muscles which cause 
the movements. 

The upper end of the humerus is enlarged, and is pro- 
vided with a hemispherical surface. This is the head, 
which in the recent condition is covered with cartilage, 
and articulates with the shallow socket on the outer angle 
of the blade-bone. To the outer side, in front, and below 
the head, the bone is rough and prominent, forming two 
well-marked tuberosities for the attachment of muscles ; 
these are called the greater" and lesser tuberosities. There 
is a groove between the two tuberosities, to the outer side 
of which the greater tuberosity lies, whilst the lesser 
tuberosity is placed on the inner side. From both these 
tuberosities prominent ridges of bone descend on either 
side of the groove, forming well-marked lips. The groove 



i8 



Humerus 



is called the bicipital groove, from the fact that in it lies 
one of the tendons of origin of the biceps muscle of the arm 

(Fig. 66, p. 113). 

The shaft of the bone, which is cylindrical above, becomes 
flattened below, so that its surfaces may be described as 
anterior and posterior. These surfaces are separated by 
inner and outer margins, which end inferiorly in two 
prominent processes, called the condyles of the humerus. 
The condyles are placed one on either side of the lower 
articular end of the bone, which is much broader from 
side to side than from before backwards. On the outer 
side of the shaft, about its middle, and formed by the 




Fig. 72. Diagrammatic section across the chest to show the relations 
of the great aerratus muscle. 



a. Head of humerus. 

b. A dorsal vertebra. 

c. Ribs in section. 



d. Breast-bone (sternum). 

e. Shoulder-blade. 

/. Serratus magnus muscle. 



recurved margin of the outer lip of the bicipital groove, 
there is a rough V-shaped impression, called the deltoid 
impression^ which affords insertion to the muscle of that 
name. The fuller consideration of the lower end of the 
bone will be delayed until the elbow-joint is described 
(see p. 149). 

The upper end and shaft of the humerus do not im- 
mediately come in relation to the surface, being enveloped 
in til© fieshy mass of the shoulder and upper arm. This 
part of the bone, however, determines to a large extent 
the general form of the limb by supporting the muscles 
which surround it. Particularly is this the case in the 



Shoulder-joint 119 

region of the shoulder, for here the large rounded head 
underlying the muscles of the shoulder imparts to it 
that roundness which is so characteristic. This is at 
once apparent, for, if from any cause the head of the bone 
is displaced, the roundness of the shoulder disappears. 

In this connexion there is one other point to be noted. 
If we examine the humerus in an articulated skeleton, when 
the bones of the limb are in a position corresponding to 
that which they occupy in the living when the arm is 
hanging loosely by the side, it will be noticed that the 
articular head of the humerus is not turned directly inwards, 
but inwards and backwards. Owing to this the great 
tuberosity of the bone is directed somewhat forwards. The 
importance of this will be at once apparent if the shoulders 
of the living be examined. In them the most prominent 
part of the shoulder points towards the front, as is repre- 
sented in the diagram (Fig. 72), and not towards the side, 
as one might naturally be led to expect (PL, p. 382). 

The shoulder-joint is remarkable for the wide range of its 
movement. The external angle of the blade-bone is pro- 
vided with a shallow hollow, called the glenoid fossa (see 
-^^gs- 57' 5^:* 59)- This is coated with cartilage, and slightly 
deepened by a ligament which surrounds its margin. The 
articular surface so formed is small compared with the 
articular area on the head of the humerus, the margin of 
the fossa not interfering in any way with the free move- 
ment of the head of the humerus, as would have been the 
case had the socket been large enough and sufficiently deep 
to have embraced a greater portion of the articular head. 

The ligaments which surround this joint and constitute its 
capsule are very loose. The joint is protected above by 
an arch, formed by the acromion and coracoid processes 
of the blade-bone, which are united by a strong ligament 
(Fig. 73, e). 

Movement in every direction may take place at the 



120 



Shoiilder-jomt 



shoulder-joint. These movements will be better understood 
if we resolve them into their simplest forms. 

There are the movements of abduction and adduction, by 
which the arm is raised from or drawn down to the side. 
Flexion and extension are movements in a forward and 
backward direction ; the latter is more limited in its range 




Fio, 73. View of the bones which enter into the formation of the 
shoulder-joint as seen from the front. 



a. Collar-bone (clavicle). 
h. Breast-bone (sternum). 

c. Acromion process of scapula. 

d. Coracoid process of scapula. 

e. Coraco-acromial ligament. 

/. Shaft of humerus ; the impression for 
the attachment of the deltoid muscle 



is just below and to the outer sida 
of the letter f. 
g. Placed on the anterior surface of 
the shoulder-blade (scapula). This 
is the surface of the bone "which is 
directed towards the chest-wall. 



than any of the others. There is the combination of these 
ibur movements termed circumduction, and an additional 
movement, that of rotation, by which the shaft of the 
humerus is turned on its long axis. If the elbow be bent 
at a right angle, and the fore-arm crossed over the front of 
the trunk, wo can by this rotatory movement of the humerus 
curry the fore-arm away from the front of the chest, at the 



Shoidder-joint 



121 



same time that we keep the elbow close to the side. The 
range of this rotatory movement is slightly more than a 
quarter of a circle. 

Another interesting observation may be made regarding 
the movements of abduction and flexion. If we raise the 
arm from the side, or bend it forwards, we can do so to 




Fig. 74. Shows the change in position of the bones of the shoulder- 
girdle when the arm is raised ; i. e. elevation of the collar-bone, and 
advance and rotation of the shoulder-blade. 



a. Collar-bone (clavicle). 



h. Shoulder-blade (scapula). 



c. Humerus. 



a considerable extent without causing any very extensive 
movement of the shoulder-blade (as may be ascertained by 
placing the opposite hand over that bone) ; but when we 
have raised the limb from the side, so as to make a right 
angle with the trunk, we find, if we continue to raise 
the arm higher, that the movement is not now taking 
place, at the shoulder-joint, but is being effected through 



122 





Latissimus dor si 123 

the rotation of the scapula, the lower angle of which can 
be readily felt advancing forwards and upwards (Fig. 74). 
The same holds good when we bend the arm forward. We 
can do so at the shoulder-joint, until we have nearly reached 
a right angle with the line of the trunk, after which the 
further movement takes place by the rotation of the scapula 
as before (Pis., pp. 44, 98, 122, 126). 

In considering the movements of the shoulder-joint 
in connexion with the muscles which produce them, it 
will be necessary to revert to what has been already said 
in relation to the movements of the shoulder-girdle. 
The first group of muscles which we considered were 
those which arose from the trunk and were inserted into 
the bones of the girdle. The second group comprises 
those muscles which arise from the trunk, and which pass 
to be attached to the bone of the upper arm. There are two 
such muscles, the latissimus dor si ^ or the broad muscle of 
the back, and the pectoralis major, or the great muscle 
of the breast. The one overlies the lower and back part of 
the trunk, the other is placed on the front and upper part 
of the chest. 

The latissimus dorsi (Fig. 75) has an extensive origin 
from the lower six thoracic spines and the spines of the 
lumbar and sacral vertebra, as well as from an inch or 
two of the posterior end of the crest of the haunch-bone. 
This origin of the muscle consists of tendinous fibres, short 
above, but increasing in length below, and forming a 
fibrous layer, which constitutes the posterior layer of the 
lumbar aponeurosis (Fig. 41, p. 69). In addition to thesa 
attachments, it also arises by fleshy slips from the last 
three ribs, slips which interdigitate with the origin of 
the external oblique in a similar manner to that already 
described in the case of the serratus magnus. At its 
origin from the lower six thoracic spines the muscle is 
overlapped by the trapezius, and it in turn overlies the 



124 Latissimiis dor si 

erector spinae, wliicli is lodged in a compartment the 
superlicial wall of which is formed by the aponeurosis of 
the latissimus dorsi (Pis., pp. 34, 38, 44, 50, 52, 94, 98, 122, 
126, 138, 162). 

The line of attachment of the fleshy fibres of the muscle 
to the aponeurosis is indicated by a curved line drawn 
from the highest point of attachment of the muscle, near 
the middle line, to its inferior attachment to the iliac crest. 
The convexity of the curve is inwards. This arrangement of 
the fleshy and tendinous fibres is important, because it is 
readily recognized on the surface of the back of a muscular 
model (Pis., pp. 34, 44, 54, 126, 162, 182). From this extensive 
attachment the fleshy fibres, converge towards the posterior 
fold of the armpit ; here they become thick, and help to form 
the roundness of that fold ; they then pass forward to be in- 
serted into the front of the upper part of the shaft of the 
humerus, to a line corresponding to the bottom of the bicipital 
groove. 

The upper fibres of the muscle are almost horizontal in 
direction, and as they pass outwards across the back they 
overlie the inferior angle of the blade-bone, to which they 
are not unfrequently attached ; here they serve a useful 
purpose in preventing the lower angle of the blade-bone 
from being separated from the chest-wall in certain move- 
ments of the limb. It sometimes happens that, as a result 
of violent muscular efl'ort, the lower angle of the shoulder- 
blade slips from under cover of the muscle. Under such 
circumstances it is not readily replaced beneath the latissi- 
mus dorsi, and a deformity results in the shape of an 
undue projection of the lower part of the scapula, thereby 
demonstrating the action of the muscle in keeping the 
blade-bono closely applied to the chest-wall. The upper 
bord<T of the muscle can usually be easily seen on the 
model just as it overlaps the lower angle of the blade-bono 
(Pis., pp. 44, 122, 126, 162, 182). 



Latissimus dor si 



125 



The lower fibres and those which spring from the last 
three ribs pass almost vertically upwards, corresponding 
very closely above to the outline of the front of the upper 
arra when the limb is hanging 
by the side (Pis., pp. 86, 122, 126, 
158, 162). 

As the fibres of the muscle 
are gathered together to be in- 
serted into the bottom of the 
bicipital groove they are natur- 
ally brought in relation to the 
external border of the blade- 
bone which is here clothed by 
fleshy muscles, around which 
the fibres of the latissimus curve, 
thus forming as it were a sling 
in which these structures lie. 
The result of this arrangement 
is that the posterior surface of 
the muscle on the back of the 
trunk becomes the anterior sur- 
face of its tendon of insertion 
in front of the arm (Fig. 75). 

The fibres of the muscle are 

comparatively thin behind, but 

form a thicker layer as they ^^^^ P^^^ ^'^ ^^^ insertion into 

the bottom of the bicipital 
pass upward and outward to the 




Fig. 75. Diagram showing 
the attachments of the latissi- 
mus dorsi muscle. The other 
muscles are not represented. 
The fleshy fibres of the latissimus 
are seen crossing the lower 
angle of the shoulder-blade, and 
turning forwards to bend on 
themselves, so that the tendon 



groove on the front of the 
humerus. This twisting of the 
muscle forms a groove or sling 
in which the fleshy part of the 
teres major muscle is placed. 



arm; there, as already stated, 

they assist in forming the thick 

fleshy fold which bounds the 

armpit behind, and which is 

best seen when the limb is raised from the side (Pis., 

pp. 148, 152, 158). 

As has been already said, the anterior border of the 
muscle overlaps the serratus magnus on the side of the chest- 



126 



Filtiiori cf thumb 

F.cx carf>i uIhAtU^ 
Ext icmmiinit\ 
iiptoruwi. 
ExU»rpi radiilii 

hrtitOT- 
Est .<!./»/ ulHsrxs. 

Smf>i»aterU>iigui-. 
Olttr*ncH I 

fiMfUff ulna, i ■ 

/.J (ondylty-^ — — ^^^ 
cf ItmmemsA ^ 

Tn^fps Uidoit 
Ti ueff, rxlcrnal luad- 

Triceps, long head. 




L'igilatioHi of scrratui magnus. 
External obligiu. 
Lumbar apoiuitrosis 

Iliac crest. 

Aponeurosis of external oblique. 
Gluteus medius. 

Tensor fasciae fcmorts. 
Gluteus nuiximus. 



JSlerHO-ntastoid. 

JTrapenus. 

Acromion process of scapula, 
.Deltoid. 

Teres r.iajor. 

Xriceps, long head. 



. Triceps, internal > 
..Triceps lek 

. J Internal eo 

' of huinenu 

'Brachialis m 

Pronator rath 

^\£icipital fasa 
\ Biceps cubiti. 
\^ 'Supinator loiigut. 
\Palmarts longns. \ 

^J^Uxor carpi ratiia^ 
^yFlcxor carpi ulnar is. 



Ili.y-libial hand. 



Pedoralis major 



127 




wall, and the interdigitation of the fibres which spring from 
the last three ribs with the external oblique muscle forms 
the continuation of the zigzag furrow, already referred to 
(p. 113), between the serratus magnus and t^e higher slips of 
origin of the external oblique. 

If the arm be raised the latissimus will assist in drawing 
it down again to the side. "With the limb by the side the 
muscle draws it downwards and backwards, and so causes 
the shoulder-blade to move slightly downwards and nearer 
the middle line. - The muscle also assists in rotating the 
upper arm inward, antagonizing the 
movement of external rotation (PL, p. 138). 
Under certain conditions the action of 
the muscle may be reversed, i. e. the fixed 
point being the attachment of the muscle 
to the humerus, the movable part corre- 
sponding to its attachment to the trunk ; 
this happens when we pull up the trunk 
as in the act of climbing. 

The pectoralis major muscle^ or great 
muscle of the breast, has been included in 
the group of muscles which spring from 
the trunk and pass to the limb. This is 
not strictly correct, as will presently be 
seen, for the muscle also arises from one of the bones of the 
shoulder-girdle ; it is, however, more convenient for our 
purpose to group it with latissimus dorsi. 

The muscle arises by fleshy fibres from the anterior 
border of the inner two-thirds or half of the collar-bone, 
i. e. from that end of the collar-bone which articulates with 
the breast-bone, from the anterior surface of the breast-bone 
on either side of the middle line, from the cartilages of the 
upper six ribs, and from the upper part of the aponeurosis 
of the external oblique muscle of the abdominal wall. The 
fibres of the muscle converge as they pass outwards to the 



Fig. 76. Diagram 
to show the mode 
in which the fibres 
of the pectoralis 
major muscle are 
inserted into the 
outer lip of the 
bicipital groove. 



J 28 Pedoralis major 

limb, the highest fibres passing downwards and outwards in 
front of the lowest fibres, which pass upwards and outwards. 
Between the two extremes they have varying degrees of 
obliquity. Those springing from the breast-bone at the junc- 
tion of its lower and middle third (not including the cartila- 
ginous portion) lie in a horizontal direction when the limb is 
hanging by the side. The tucking in of the lower fibres 
behind the upper as they pass from the chest-wall to the 
arm leads to an increase in the thickness of the fleshy fold 
which bounds the hollow of the armpit in front. By this 
convergence and infolding of the fibres of the muscle it be- 
comes much narrowed, and is inserted by means of a flat 
tendon about 2\ inches in breadth into the outer lip of the 
bicipital groove of the humerus (Fig. 76). The muscle is 
superficial throughout, except at its tendinous insertion, where 
it is overlapped by the deltoid or great muscle of the shoulder 
(Pis., pp. 58, 62, 72, 86, 148, 152, 158, 382). The great 
pectoral muscle overlies the lesser pectoral. When the 
arm is raised above the head, however, the lower border 
of the lesser pectoral is for a short distance uncovered and 
imparts a roundness to the lower part of the anterior 
axillary ^ fold. 

The fibres of the great pectoral which spring from the 
collar-bone are usually separated from the fibres which 
arise from the breast-bone by a shallow furrow passing 
obliquely downwards and outwards from the inner end of 
the collar-bone. The distinctness of this furrow on the 
surface depends on the development of the muscle and 
the position of the limb (PL, p. 58). The fleshy fibres which 
spring from the breast-bone and ribs form a triangular mass, 
the apex of which overlies the front of the upper arm, 
while the base corresponds to the surface on either side of 
the middle line of the breast-bone. The prominence caused 

' The term 'axilla' is used by anatomists for the hollow of the 
ariii^iit. 



Pedoralis major 129 

by these fibres forms the sides of the median furrow, the 
bottom of which corresponds to the breast-bone. The 
angles formed by the base and sides of the triangle above 
and below are rounded off. The upper side of the triangle 
lies contiguous with the lower border of the portion of the 
muscle which arises from the collar-bone. The lower side 
of the triangle is almost horizontal in its inner half, where 
it overlies the chest-wall, but, curving slightly upwards as 
it passes from the chest to the limb, corresponds to the lower 
border of the anterior fold of the armpit. From the round- 
ing of the angles of the. base of this fleshy mass it follows 
that the median furrow, which on the surface corresponds to 
the interval between the two muscles, is opened out above and 
below in front of the upper and lower ends of the osseous 
part of the breast-bone. The latter is at some little distance 
above the pit of the stomach, which it may be remembered 
corresponds to the position of the cartilaginous portion of 
the breast-bone (Pis., pp. 58, 62, 72, 86, 152, 158). 

It occasionally happens in persons of great muscular 
development that bundles of tendinous fibres pass from the 
origin of one muscle across the middle line of the breast- 
bone to the opposite side, and when the muscle is powerfully 
contracted these may stand out as more or less prominent 
cords crossing and slightly interrupting the smoothness of 
the central breast furrow (PL, p. 382). Oftentimes, too, 
the lower and internal attachment of the muscle can be 
recognized as a series of slight elevations corresponding to 
the lower flesh}^ slips of origin. The lower border of the 
muscle corresponds usually to the cartilage of the fifth rib, 
or to a line drawn outwards and slightly upwards from the 
pit of the stomach. 

When well developed, the muscle completely conceals the 
framework of the thoracic wall, which it overlies, but in 
cases where the muscle is thin the ribs and rib cartilages 
may be recognized beneath it. Passing as it does from the 



130 Pedoralis major 

breast to the upper arm, the muscle conceals the rounded 
form of the chest, except in front where it is supported on 
the convex surface of this part of the trunk, the fullness of 
which it carries towards the upper part of the limb, thus 
imparting an appearance of width to the chest and causing 
it to blend externally with the general roundness of the 
shoulder. 

The pectoralis major draws down the uplifted arm ; it 
may also draw forward the limb; and thus counteract the 
influence of the latissimus dorsi, which draws the arm back ; 
it assists that muscle, however, in effecting inward rotation 
of the limb. The lower fibres of the muscle assist in de- 
pressing the shoulder, whilst the upper fibres, which spring 
from the collar-bone, help to bend the arm forwards at 
the shoulder-joint. The sternal fibres also draw forward 
the shoulder. When the shoulders are thrust forwards the 
muscle is not pulled away from the chest-wall, but becomes 
bent upon itself so as to form a broad and shallow furrow 
which crosses the muscle from above, downward. It will be 
remembered that the principal muscle concerned in this 
action is the serratus magnus, which pulls forward the 
shoulder-blade and with it the shoulder. The hollowing of 
the pectoral muscle is due to the slight folding which 
takes place as it crosses in front of the armpit, the laxity of 
the tissues there permitting greater mobility. 

These various actions of the muscle are reversed when the 
limb becomes the fixed point, as in the act of climbing; it 
then assists in drawing up the trunk towards the fixed limb. 

The surface forms over the muscles vary very much in the 
two sexes; what has been already stated applies princi- 
pally to the male. In the fat which overlies the muscle 
the breast or mammary gland is situated. In the male the 
only indication of the breast is the nipple, for the glandular 
part is not developed, although in some cases a slight 
accumulation of fat in the region of the nipple imparts 



The Breasts 131 

a prominence to that point. The position of the nipple is 
a variable one, but it usually lies opposite the interval 
between the fourth and fifth ribs. If a line be drawn 
from the navel to the joint between the collar-bone and 
the acromion process of the shoulder-blade it will fall over 
the position of the nipple on a level with the interspace 
between the fourth and fifth ribs. 

In the female the breasts are glandular, and their develop- 
ment depends largely on age and other conditions. As they 
lie on the surface of the pectoral muscles the breasts should 
be widely separated from one another ; this will vary ac- 
cording to the width of the chest-wall. In cases where that 
is narrow, the glands are necessarily brought closer together. 
The nipples should be directed forward and slightly outward 
so as to point away from each other. The breasts should 
not be unduly large, and their consistence should be such 
as to counteract the influence of gravity ; there should be 
no fold or crease of the skin below them, but they should 
rise gently from the general surface. As Professor Briicke 
has pointed out, the angle formed by the apex of the cone 
should nearly approach a right angle, the lower part of the 
organ being slightly more convex and rounded (Pis., pp. 72. 
80, 86, 124, 132, 262, 270, 438). 

In regard to the level at which the female breasts are 
placed, this will vary somewhat in different models, but 
the effect produced is always more pleasing when they 
are set high and combined with the general roundness of 
the neck and shoulders than when they are situated on 
a somewhat lower level. 

In some models the areola, or tinted area which surrounds 
the nipple, is slightly elevated from the surrounding surface 
of the breast, a feature which is sometimes represented in 
modern sculpture. The breasts themselves are movable, 
a circumstance which accounts for the fact that in the erect 
posture they lie at a somewhat lower level than in the 

K 2 



132 The Breasts 

recumbent position, when tliey are no longer influenced by 
their own weight. 

What has been said regarding the form of the breasts 
will require modification if it be the artist's intention to 
represent a matronly form ; in this case the changes in the 
gland dependent on the maternal function will have given 
rise to alterations in its development and consistence which 
materially affect its form, greater fullness and a slight 
folding of the tissues beneath the breasts being permissible 
under such conditions. 

The existence of these glands in the female, and the 
presence of ah abundant quantity of fat, naturally mask the 
form of the great pectoral muscle on the surface of the body. 
The lower border of the muscle is concealed, and the lower 
part of the anterior fold of the armpit is effaced by the 
extension of the rounded base of the gland across it (Pis., pp. 
72, 80, 86, 124, 132, 262, 270, 438). Above, however, the fold 
of the armpit appears distinct where the muscle escapes from 
under cover of the breast. There is usually a considerable 
quantity of fat overlying the fold here, and the surface 
form presents a smooth, slightly convex surface extending 
from the collar-bone above- to the somewhat thick and 
rounded border of the fold of the armpit below. Over this 
part of the great pectoral muscle there is an elevation on 
the surface distinct from that of the breast, the conical 
form of which rises gradually from this surface (Pis., pp. 72, 
80, 86, 132, 438). These points may be readily recognized in 
a well-formed model, and may be further demonstrated by 
raising the limb from the side, in which position the fold 
of the armpit is more distinctly seen. At the same time it 
will bo noticed that the act of raising the arm exercises 
a certain amount of traction on the breast, which lies higher 
on the side with the uplifted limb than on the opposite 
side if the arm is pendant (Pis., pp. 132, 434). 

"We have next to turn our attention to that group of 



Deltoid 133 

muscles which arises from the bones of the shoulder- girdle 
and passes to be inserted into the bone of the upper arm ; 
the most important of this group is the deltoid or great 
muscle of the shoulder. There are others which take their 
origin from the surfaces of the blade-bone, but these for 
the most part lie deeply, and do not influence the surface 
forms except in so far as they constitute a padding for 
the more superficial muscles which overlie them. It will 
be necessary, however, to refer to two of them, the infra- 
spinatus and the teres major^ because they are in part 
superficial. The coraco-hrachialis muscle also arises from 
the blade-bone (coracoid process) and is inserted' into the 
humerus, but its consideration had best be delayed until 
the surface forms of the upper arm are discussed. 

The deltoid muscle, which is superficial throughout, forms 
the cap of the shoulder. As its name indplies, it is trian- 
gular in shape, and is so called from its resemblance to 
the Greek letter A. The base of the triangle is directed 
upwards and is attached to the girdle-bones, the apex or 
pointed extremity of the muscle passes down towards the 
middle of the outer side of the upper arm. 

The muscle arises from both bones of the shoulder-girdle, 
from the anterior surface of the external third of the collar- 
bone in front, above the shoulder from the point and outer 
margin of the acromion process of the shoulder-blade, and 
behind from the lower border of the spine of the scapula 
in its whole length. The origin of this muscle is thus seen 
to correspond to the insertion of the trapezius, indeed we 
may regard it as a prolongation of that muscle downward to 
the limb, the bones of the girdle forming an interruption 
to the direct continuity of the muscular fibres. 

The fibres of the muscle, which arise from the bony origin 
just described, are arranged in fleshy bundles which con- 
verge inferiorly to form a strong thick tendon which 
•4s inserted into that rough V-shaped surface, already 



134 Deltoid 

described (p. ii8\ on the outer side of the shaft of the 
humerus, about its middle. This raised V-shaped surface is 
hence called the deltoid eminence. The thickest part of 
the muscle corresponds to its central fibres; in front, the 
anterior border of the muscle lies alongside the outer margin 
of the clavicular fibres of the great pectoral, from which it 
is separated by a linear depression which is wider above, 
as the two muscles are slightly separated from one another 
at their origins from the collar-bone. In corresponderce 
with this, on the surface of the shoulder in front, there is 
a slight hollow below the collar-bone overlying the interval 
between the muscles. From this there passes down a linear 
furrow, which follows the line of separation between the 
two muscles towards the external limit of the anterior fold 
of the armpit where the tendon of the insertion of the 
great pectoral sinks under cover of the deltoid. These 
surface depressions are best seen in a muscular model with 
little or no superficial fat, and are of course intensified 
when the muscles are powerfully contracted. They are 
absent in the female, or, if present, are very much softened 
on account of the quantity of fat and the feebler muscular 
development (Pis., pp. 38, 58, 62, 72, 86, 104, 148, 152, 382, 

434)- 

The posterior border of the deltoid is much thinner. 
Owing to the fact that it is intimately connected with 
a strong aponeurosis which stretches across the lower part 
of the blade-bone, it has much less influence on the surface 
contours, though if the arm be raised over the head the 
outline of this border may be traced upon the surface 
(Pis., pp. 34, 38, 44, 50, 52, 54, 94, 98, 122, 126, 138, 162, 
262, 270). 

TIkj roundness of the muscular mass of the deltoid is due, 
as lias been already stated, to the fact that it overlies the head 
of lli(! liumerus and receives support from that portion of the 
boil.-. This ;dso explains why the most prominent point of 



Deltoid 135 

its general roundness is directed forwards and outwards, the 
anterior part of the muscle appearing much fuller than the 
posterior, which presents a somewhat flattened appearance 

(PI, p. 382). 

The greatest width of the shoulders, however, does not 
correspond to the points at which the deltoid muscles over- 
lap the head of the humerus, but is situated at a somewhat 
lower level, where the various bundles of fibres are gathered 
together to pass to their insertion. This point is usually 
found to correspond to the level of a line drawn outwards 
across the limb in continuation with the lower border of the 
anterior fold of the armpit (Pis., pp. 58, 86, 382). 

The surface form does not convey a correct impression 
of the extent to which the muscle descends to be attached 
to the shaft of the humerus, for the insertion is obscured 
both in front and behind by the fleshy muscles of the upper 
arm, between which its tendinous fibres pass to a much 
lower level than might at first seem likely. According to 
the amount of fat present a depression more or less distinct 
appears on the surface overlying the point of junction of 
the fleshy fibres with the tendon of insertion. It is most 
pronounced when the arm is raised and slightly drawn back 
and the muscle powerfully contracted. Leading up from 
this hollow on either side are the linear furrows corre- 
sponding to the anterior and posterior borders of the muscle 
respectively (Pis., pp. 44, 50, 52, 54, 72, 94, 98, 104, 126, 182, 
382). 

The origin of the deltoid is much better seen when the 
limb is raised. It then corresponds to a furrow which over- 
lies the outer third of the collar-bone, the upper surface of 
the acromion and the spine of the scapula, over the middle 
of the latter of which it gradually fades into the general 
fullness of the trapezius. The depth of the furrow, which 
is greatest, in the uplifted position of the limb, over the 
acromion, depends on the development and state of contrac- 



136 Action of the Deltoid 

tion of the trapezius and deltoid muscles which lie above and 
below it (Pis., pp. 38, 44, 94, 98, 122, 126, 434). This furrow, 
which is seen in the female when the limb is raised, is 
much softer in its contours, owing to the greater thickness 
of the superficial fatty layer (Pis., pp. 262, 270). As has 
been pointed out to me by my friend Mr. Pilcher, it is not 
uncommon, particularly in women with plump shoulders, 
to meet with a dimple overlying the angle formed by the 
acromion process as it passes forwards from the spine. 

The action of the deltoid varies according to the part of 
the muscle brought into play. It assists in raising the arm. 
That part of the muscle which arises from the acromion 
draws the arm upwards and away from the side ; the anterior 
fibres raise the limb and bend it forwards ; the posterior 
fibres elevate the limb and pull it backwards. The action 
of the muscle is checked by the ligaments around the 
shoulder- joint, so that in the act of raising the limb from 
the side further movement at the shoulder-joint ceases when 
the arm forms a right angle with the trunk. Any further 
movement in an upward direction is due to the rotation of 
the shoulder-blade itself ; this movement has been previously 
described (p. 115). During powerful contraction of the 
muscle the surface forms over it frequently display the details 
of the arrangement of its fibres, a series of shallow furrows 
indicating the lines of separation of the different bundles ; 
these are best seen near the bony origin (Pis., pp. 98, 182). 

Of the two remaining muscles of this group little need 
bo said. The infraspinatus arises from the posterior surface 
of the blade-bone below the spine ; its fibres converge 
externally to end in a tendon which is inserted into the 
back of the great tuberosity of the bone of the upper arm. 

The muscle is triangular in shape. In close relation to 
it.s lower border we find another muscle which is called the 
teres minor. The fibres of this muscle lie parallel to those 
of the inira-spinatus, and are attached along the external 



Infraspinatus and Teres minor 137 



border of the blade-bone. The fibres pass upwards and 
outwards towards the great tuberosity of the humerus, into 
which they are inserted immediately below the infra-spinatus. 
In regard to their action and their influence upon the 
surface forms these two muscles may be regarded as one ; 
they both act as rotators outwards of the bone of the upper 
arm; they assist also in drawing the arm backwards, and 





Fig. ']']. Diagram showing the 
attachments of the infra-spinatus 
and teres minor. The two muscles 
are treated as one fleshy mass. 

a. Supra-spinous fossa. 
h. Acromion process. 

c. Eoot of spine. 

d. Humerus. 

e. Upper angle of shoulder-blade. 
/. Lower angle of shoulder-blade. 

g: Infra-spinatus and teres minor. The 
dotted line represents the outline 
of the deltoid. 



Fig. 78. Diagram showing the 
attachment of the teres major. 

a. The infra-spinous fossa' of the blade- 
bone, from which the infraspinatus 
muscle and teres minor have been 
removed. 

6. Acromion process. 

c. Eoot of spine. 

d. Humerus. 

e. Upper angle of blade-bone. 

f. Lower angle of blade-bone. The 

dotted lines represent the outlines 
of the deltoid above and the latis- 
simus dorsi below. 
h. Teres major. 



the teres minor helps to pull down the uplifted limb (Fig. 
77). Both muscles are covered by a fairly strong and tough 
layer of fascia, a circumstance which explains why they 
do not produce a greater surface relief when they are in 
a state of contraction. The portions of these muscles which 
are subcutaneous correspond to a somewhat triangular area, 
which is mapped out by the reliefs formed by the edges of 
the trapezius within, the deltoid above, and the upper 





iJ 



V 

I 



^ -^ 



■9 ia 



■3 3 t 

''••&- "^ ^. >- 
■^ ■ =• t 3 



S -a « I 



a ^ 
^ I 

St 

S! 



2 -Q 



-2 J ^5. 1^^ 



S 2^ 



a S- 






^ lu a <! <3 

a 3 S <s -s: 



o 



Teres major 139 

border of the latissimus dorsi below. The surface of these 
muscles so exposed forms a slight relief bounded by the out- 
lines above described. These points may be seen best when 
the shoulders are drawn back. When the limb is raised 
above the head, the surface form is modified by the rotation 
of the blade-bone, the inferior angle of which is carried 
forwards and slightly upwards. In this position the inner 
border of that bone is rendered more apparent, and the 
lower part of the rhomboideus major is more fully exposed 
(Pis., pp. 34, 38, 44, 50, 52, 54, 94, 98, no, 122, 126, 138, 
142, 182). 

The last muscle of this group which we have to consider 
is the teres major. It takes origin from the posterior 
surface of the lower angle of the blade-bone ; its fibres run 
upwards and outwards parallel to those of the teres minor, 
but in place of being attached to the back of the humerus 
the teres major runs forward to the front of the shaft of 
that bone and is inserted into the inner lip of the bicipital 
groove. The muscle, when well developed, forms a thick 
fleshy mass. Its relations to the latissimus dorsi and the pos- 
terior fold of the armpit are important. As has been already 
stated, the latissimus dorsi folds round the outer border of 
this muscle so as to enclose it like a sling. As the fibres 
of the latissimus sweep round the thick teres major muscle 
the latter imparts a fullness to them which accounts for the 
thickness of the posterior fold of the armpit. The teres 
major acts as a rotator inwards of the arm, thus antagonizing 
the action of the teres minor. Acting in conjunction with 
the minor it draws down the uplifted limb (Fig. 78). 

The muscle imparts a fullness to the surface which overlies 
the outer border of the blade-bone. With the limb by the 
side and forcibly rotated inwards, the muscle forms a well- 
marked elevation between the upper border of the latissimus 
dorsi and the teres minor. This relief, externally, sinks 
under cover of the deltoid and the long head of the great 



I40 Siimniary of the Muscles of the Back 

extensor muscle on the back of the upper arm, called the 
triceps. It is owing to the presence of this muscle that 
the external or axillary border of the blade-bone exercises 
so little direct influence on the surface forms (Pis., pp. 44, 50, 
122, 126, 148, 152, 158, 162, 182). 

Having now considered in detail the various superficial 
muscles which lie on the back of the trunk, it may be well 
to review briefly the main features of the superficial anatomy 
of this region. Arising from the middle line of the back, 
throughout the entire extent of the thoracic region, and ex- 
tending upwards as high as the back of the skull, is the 
trapezius. The fibres of insertion are to be traced outwards to 
the bones of the shoulder-girdle. The higher fibres, which 
pass forward to be attached to the outer third of the front 
of the collar-bone, have a downward direction. The lower, 
which are inserted into a tendon overlying the root of the 
spine of the shoulder-blade, have an upward direction. The 
intermediate fibres run with varying degrees of obliquity 
to be inserted into the upper margin of the spine and the 
acromion process of the blade-bone (Pis., pp. 34, 52, 54, 94, 
98, no, 138, 182). 

The origin of the deltoid corresponds precisely to the 
insertion of the trapezius, the collar-bone and the bony 
processes of the blade-bone alone separating the attach- 
ments of these muscles. The fibres of the deltoid are 
gathered together to form a pointed tendinous insertion, 
which is attached to the outer side of the shaft of the 
bone of the upper arm, about its middle. The muscle 
thus covers the shoulder-joint behind, in front, above, and 
to the outer side (Pis., pp. 34, 52, 54, 94, 98, 104, no, 122, 138, 
148, 152, 162, 182). 

Arising from the middle line of the back, throughout 
tli<} entire region of the loins, and also Irom the lower 
lialf of the thoracic region, is the latissimus dorsi. The 
latter part of its origin is overlapped by the pointed lower 



Summary of the Muscles of the Back 141 

fibres of attachment of the trapezius. In addition, the 
latissimus dorsi arises from the last three ribs as well 
as from the hinder end of the iliac crest for a variable 
distance, as has been already described. The fibres pass 
upwards and outwards with varying degrees of obliquity 
towards the hinder fold of the armpit, the contour line 
of which they form : here the muscle is twisted on itself 
to reach the front of the upper part of the shaft of the 
humerus into which it is inserted (Pis., pp. 34, 38, 44, 50, 
52, 54j 94. 98, 122, 126, 138, 152, 158, 162). 

A triangular interval between these muscles in the 
scapular regions is to be noted, the apex of which corre- 
sponds to the root of the spine of the blade-bone. Of 
its sides, the inner corresponds to the outer margin of the 
trapezius, the outer to the posterior border of the deltoid, 
while its base, somewhat curved, coincides with the upper 
border of the latissimus dorsi. It is within the area so 
defined that the blade-bone, and some of the muscles con- 
nected with it, come into direct relation to the surface. 
"With the limbs by the side we recognize, in this triangular 
interval, the internal border of the blade-bone. To the inner 
side of this border, we note the presence of that portion of 
the rhomhoideus muscle which is uncovered by the trapezius. 
Arising from the posterior surface of the blade-bone below 
the spine, we see as much of the infraspinatus and teres 
minor as is uncovered by the deltoid, while, corresponding 
to the lower angle and external border of the blade- 
bone, as much of the teres major as is not overlapped by 
the latissimus dorsi is displayed (Pis., pp. 34, 94, 98, 138, 
182). 

The relations of the boundaries and contents of this 
triangular area, which, for descriptive purposes, may be 
called the scapular triangle, vary from one or other of two 
causes or a combination of both. These causes depend on 
the mobility of the blade-bone or scapula. 



142 Summary of the Muscles of the Back 

Firstly, the relation of this scapular triangle to the surface 
will alter according as the blade-bone is raised or lowered 
or drawn backwards or forwards, movements which take 
place when we raise or lower the shoulders or when we 
brace them back or pull them forwards (Pis., pp. 50, no, 

138). 

Secondly, the outlines of the scapular triangle and its 

contents will be much modified by that movement of the 
scapula which is called rotation, and which has been already 
considered in detail. This is the movement which causes 
the inferior angle of the blade-bone to advance on the 
chest-wall, whilst its upper angle passes nearer the middle 
line, a movement which takes place to greatest extent 
when the arm is thrown above the back of the head or 
neck (Pis., pp. 38, 44, 98, 122, 126, 142, 270). Rotatory 
movement in an opposite direction is produced when the 
arm is carried across the back of the trunk towards the 
opposite side of the body. In this position the- lower angle 
of the blade-bone is drawn nearer the middle line of the 
back, whilst the upper angle passes to lie wide of the middle 
line (PI., p. 162). 

As will bo obvious, there may be many combinations of 
these movements. Two examples will be sufficient to render 
this clear. Wc may have the unlifted arm with the shoulder 
thrown forwards, or, on the other hand, the uplifted limb 
with the shoulder drawn back — in these positions the 
arrangement of the contents and outlines of this scapular 
triangle will display very characteristic differences; these 
tho student will best appreciate for himself by a study of 
Pis., pp. 38, 44. 50, 98, 122, 126. 162, 182. 

The only remaining superficial muscle which it is neces- 
sary to study here is a portion of the external ohlique as it 
forms the flank ; this is visible in a view of the superficial 
muscles of the back, since it lies wide of the lower attach- 
ment of the latissimus dorsi to the ribs and iliac crest. 



Summary of the Muscles of the Back 143 

Usually, however, the superficial layer of fat in this region 
is so abundant that the surface contours are not much in- 
fluenced by the development or contraction of this part of 
the external oblique (Pis., pp. 38, 44, 126, 162). 

"Whilst the muscles above mentioned constitute the super- 
ficial layer of the back, the student must not overlook 
the fact that many of the dee per muscles exercise a very- 
marked influence on the surface forms. Most important of 
these are the erectores spinae. These control to a large extent 
the movements of the vertebral column, and though their 
action has been already fally discussed, it may be well here to 
remind the student that when the figure is represented in 
poses in which the back is bent either forwards or backwards, 
to the side, or twisted, these muscles undergo remarkable 
modification in their outline and the degree of their contrac- 
tion. This will necessarily react on the surface contours, 
for, as has been previously stated, the muscles which overlie 
them are frequently so thin and tendinous that the deeper 
muscles exercise a much greater influence on the surface 
form than those which overlie them (Pis., pp. 38, 44, 50, 52, 
54, 98; 162). 

An examination of PL, p. 50, will bsst explain this. It 
may be well here to emphasize the fact that when the figure 
is bent forward the central farrow of the back becomes 
shallower, and may be replaced by a ridge corresponding 
to the tips of the spines of the vertebrae ; the fleshy column 
of the erectores spinae, which lie on either side, are flattened, 
owing to the stretching of their fibres : whereas if the figure 
be bent backwards the median furrow is deepened and the 
erectores spinae are rendered more prominent, owing to the 
fact that they are now in a powerful state of contraction. 
The median furrow of the back in the upper thoracic 
region may be further deepened by the approximation 
of the blade-bones to the middle line, an action which is 
induced by the powerful contraction of the trapezii, and 



1^^ The Female Back 

the sliorteniug and bulging of their fibres, a condition 
which is represented in Pis., pp. 44, no, 138. 

In concluding this resume it need only be added that 
the diiference between the sexes is in great part due 
to the fact that in woman the superficial fatty layer is 
present in such quantity as to mask, to a greater or less 
extent, the details above described. In the female we do 
not expect to find so powerful a muscular development as 
in the male ; the result is that, though in woman the surface 
contours depend on the same structures, in her the outlines 
are more rounded and soft, affording little if any evidence 
of many of the above details (Pis., pp. 36, 52, 54, 142, 270, 
278> 



CHAPTER VI 



THE UPPER APtM 



Befoee passing to the consideration of the surface forms 
of the upper arm, it may be well to glance for a moment 
at the manner in which the arm springs from the trunk. 
When the arm is hanging by the side there is a hollow, 
called the armpit^ between the upper part of the limb and 
the chest-wall. If the fingers be thrust into this space the 
anterior and posterior walls of the hollow will be found to 
be thick and fleshy. . These have been already frequently 
referred to as the anterior and posterior folds of the armpit, 
and have been seen to be formed by the muscles passing 
from the trunk to the limb. 

Great alterations take place in the form of this hollow 
when the arm is raised from the side. Its boundaries are 
now better seen, for the borders of the anterior and 
posterior folds are stretched, and more clearly defined 
(Pis., pp. 62, 148, 152, 434). 

The most noticeable feature in connexion with them is 
that the posterior fold extends farther down the limb than 
the anterior ; in consequence of this, if the figure is looked 
at from the front, when the arm is raised, we can see into 
the hollow of the armpit. In this view the anterior 
surface of the posterior wall is in part exposed, and we 
have to account for the structures which determine its form. 
If, on the other hand, the figure is sketched from behind 
when the arm is uplifted the posterior fold of the armpit, 
being deeper, conceals from view the hollow, and the lower 
margin of this fold forms the outline of the figure in this 
position (Pis., pp. 38, 44, 94, 162, 182). Viewed from the side, 



146 The Armpit 

we cau of course recognize both boundaries, and get a better 
idea of the inner wall of the space. 

For clearness of description the boundaries of the space 
had now better be described. In form the hollow resembles 
a four-sided pyramid, the sides of which are unequal. The 
base of the pyramid corresponds to the skin which overlies 
the hollow. The inner wall of the space is formed by the 
chest-wall overlain by the serratus magnus. The anterior 
wall, as has been already stated, is constituted by the pectoralis 
major and minor. The posterior wall is in part made up of 
the anterior surface and external border of the blade-bone, 
both of which are clothed by muscles, a muscle called the 
subscapularis being placed upon its anterior aspect, whilst 
the fleshy fibres of the teres major cover its external 
border. The thickness of this latter muscle is sufficient to 
mask the outline of the external border of the bone, which 
the student can easily feel by grasping firmly the posterior 
fold of the armpit when the limb is raised. Sweeping 
round the outer border of the teres major the fibres of the 
latissimus dorsi can readily be seen in a dissection of this 
rogion, and in certain positions of the limb their presence 
causes distinct alterations of the surface forms (Pis., pp. 148, 
152, 158. 434). The anterior and posterior walls of the armpit 
are wide apart as they pass from the trunk, but as the 
muscles which form them— with one exception, the pectoralis 
minor— are all inserted into the bone of the upper arm the 
folds are necessarily brought much closer together at their 
attafhmcnts to the limb. 

The outer wall of the space is necessarily much narrower 
than the others, and consists of the upper portion of the 
shall of the humerus and certain muscles which are passing 
down ulrjTig its inner side. These are the Uceps muscle 
of the arm and the coroco-hrachialis^ which will presently 
bo described. The hollow itself is filled with fat, in which 
the largo vessels and nerves of this region are embedded. 



I 



Coraco-brachialis 



147 




It is owing to the presence of these contents, and also 
to the stretching of the skin and fibrous layers which form 
the base of the space, that the hollow is not so deep as one 
would expect from a mere study of the muscles alone. 

The plates on pp. 62, 132, 148, 152, 158, and 434 repre- 
sent the figure with the 
limb in different positions, 
and the student will be 
able to form a bstter idea 
of the arrangement of the 
muscles by a study of these 
plates than by any verbal 
description. 

This is a convenient 
point at which to study 
the coraco-hrachialis ; it 
arises, in conjunction with 
the short head of the 
biceps muscle of the arm, 
from the tip of the cora- 
coid process of the blade- 
bone, and is inserted into 
the inner side of the hu- 
merus, where its attach- 
ment corresponds to the 
middle third of the length 
of the shaft. The upper 
part of the muscle is con- 
cealed by the anterior fold 
of the armpit, and as it runs down along the inner side of 
the shaft of the humerus it is overlapped, when the limb 
is hanging by the side, by the fleshy fibres of the biceps. 
"When the arm is raised and the borders of the armpit are 
stretched, the muscle can be readily recognized as a distinct 
elevation running along the inner side of the limb, between 

L 2 



Fig. 79. A view to show the struc- 
tures whith underlie the deltoid and 
great, pectoral muscles, the outlines of 
which are represented by dotted lines. 
The separation of the clavicular fibres 
from the sternal fibres of the great 
pectoral is also shown by a dotted 
line. 

a. Collar-bone (clavicle). 
h. Breast-bone (sterniim). 

c. Acromion process ot scapula. 

d. Coracoid process of scapula. 

e. Pectoralis minor muscle. 
/ Coraco bracliialis muscle. 

g Short head of bicei)S muscle. 
h Long head of biceps muscle. 
k Humerus. 



1 Breast boric (sicnium). 

2 IIolliKc of armpit. 

3 Pcctoralis major, sternal fibres 

4 Triceps, outer head. 

5 Latissimus dorsi. 

Posterior border of ulna. 

; f-lcxor mass. 

; : Supiftator longiis. 

I ; ; Bicipital fascia. 

\ \ j : Brachialis aniictis 

; ; / / .' Biceps C2ibiti. 

: ; / / /' ; .Deltoid. 



Brachialis anticu. 

Biceps cubil 

Triceps tendon and Olecranon pro 

Anconeus a7id Ext.condyl 

Supinator longu. 



, Sierno-mastoid. 
,'Pit of neck. 
^.■Trai>ezius. 
cromion 
scapu> 




Internal cmidyle. 
Triceps, ijuier head. 

Triceps, long licad: \ ', / 

Coraco-brachialis'. 1 / / 
Teres major. ; /'/ 

Latissimus dorsi'. • f 
Pcct. major, sternal fbres'./// 
D imitations ofserratus magi'.y ' 
Digitations of ext. oblique:' , ' ' 

Pit of stomach'. ' /.' 
I\ectfem.aiui Lineae trans'.'-' ' ' 

External oblique.' ' ,. 
Iliac crest.'' ' , - 
A ntcrior sup. iliac spine.' ' ' ' 

(jlutcus mcdiiis.'' .,- 

Tensor fasciae fcmor is.' " ..- 

AponcuK of ex t. oblique.'' ,- 

Pouparts ligament.--' ' , . - 

iFw-psoas.'' ' 

Pcct incus:' 

I lio-tibial band.- 

Adductor longus. " 

Gracilis: — 
Vastus extcrnus. 
Sartorius 
Pectus femoris. 
Vastus iftternus.-- 
Band of Richer.- - 

1 1 Posterior border of ulna. 

I 'J lixtensor carpi radialis loiigior. 
1 3 /: x tensor carpi utnaris. 

I I f'.x tensor carfi radialis brrjior. 
1-' Extensor communis digitorum. 



Sartorii 

Vastus ( 

Rectus j: 

Vastus in 

-J lio-tibial i 

Band of P> 

Extensors of thunu 

Tendon of Extensor carpi uhtari 

Head of ulih 

Annular ligame^it of wris 

Extensor secundi i7iier7iodii pollici 



Humerus 149 

the attachments of the folds of the armpit to the limb. 
This elevation is distinct from, and lies behind, that formed 
by the upper portion of the biceps, and can be traced 
down along the inner side of the upper arm, gradually 
fading away about the middle of this portion of the limb. 
The muscle is most strongly marked in such positions as 
we see represented in pictures of the Crucifixion, but an 
examination of the plates on pp. 152, 158, 212, and 434 will 
sufficiently demonstrate the influence which it has on the 
surface forms. As will be seen, it is separated in front from 
the anterior wall of the armpit by the biceps, whilst behind 
it overlies the posterior fold jusb where the muscles which 
constitute that fold, viz. the latissimus dorsi and teres 
major, are inserted into the upper portion of the shaft of 
the humerus. The coraco-brachialis assists in raising the 
arm at the shoulder-joint; it also tends to turn the limb 
forwards and inwards towards the middle line of the body 
(Pis., pp. 148, 152, 158, 170, 176, 212). 

Before passing to consider the muscles of the upper arm 
it will be necessary to describe the bones with which they 
are connected. 

The humerus^ or bone of the upper arm, has been in part 
described (Chapter V, p. 117), but its lower end must now 
be examined in greater detail. 

The lower extremity of the humerus enters into the 
formation of the elbow-joint This joint unites the bone of 
the upper arm with the two bones of the fore-arm. The 
latter lie side by side, and are called — the inner bone, the 
ulna, the outer bone, the radius. 

The shaft of the humerus, which about its middle is more 
or less prismatic in section, becomes expanded inferiorly. 
It acquires a flattened form, and displays, as has been 
already stated, well-marked anterior and posterior surfaces, 
which are separated on the inner and outer sides by dis- 
tinct margins. If traced downwards these margins will be 



i=;o 



Humerus 



loiind to terminate in pointed processes called respectively 
the inner and outer condyles. Of these condyles the 



d 



^ 



\ % 



k I 

Right humerus. 
Fia. Zo. Front view. Fia. 8 1. Outer side. Fig. 82. Dack view. 




a. Heitd. 

b. Orcatur tuberoiity. 
c IxiiMM-r tuboroHity. 
(1. liicipital ((roove. 

e. Doltuid impruaiiion where deltoid 

tntiAclu iri iiiHortcd. 

/ Internal coniiyl(<. 

1/ KsUtrual condylu. 



h. Capitellum for articulation with head 

of radius. 
*. Trochlear surface for articulation 

with ulna. 
j. External condyloid ridge. 
k. Internal condyloid ridge. 

These ridges afford attachment to the 

external and internal intermuscular 

septa lesptctively. 



inner in tlio more prominent, whilst of the ridges leading 
to thorn (called mpra-condyloid ridges) the outer is the 



Humerus 151 

better marked. These ridges and processes are of great im- 
portance in affording attachment to numerous muscles and 
processes of fascia in this region. The part of the humerus 
which lies between the two condyloid processes is much 
thickened and is curved slightly forward. It is on this 
portion of the bone that the articular surfaces are placed 
by means of which it is jointed with the radius and ulna. 

Just below the external condyle and to its inner side 
a smooth rounded surface, called the capifellum or little 
head, is noticed. This process, which lies more on the front 
of the lower extremity of the humerus than on its inferior 
aspect, is adapted to articulate with the shallow hollow on 
the upper end of the outer bone of the fore-arm (radius). 
To the inner side of this little articular head, the lower 
end of the humerus is grooved by a pulley-like surface 
which passes round it in a slightly spiral manner from 
back to front. This is called the trochlea, and is for 
articulation with the inner bone of the fore-arm (ulna). 
The trochlea is separated from the capitellum by a slight 
smooth ridge, whilst its inner border is defined by a well- 
marked and prominent edge. The latter is separated by 
a considerable interval from the internal condyle of the 
humerus, which lies above it and to its inner side. It is to 
this fact that the internal condyle owes its prominence. 

As has been already stated, there are two bones in the 
fore-arm — the radius and the ulna. Now it must be borne 
in mind that these two bones are not immovably united, as 
is the case with the corresponding bones of the leg, but are 
freely movable on one another in certain directions. This 
may be best understood if we compare for a moment their 
relations to each other in different positions of the limb. If 
the arm be held with the palm of the hand directed upwards, 
the bones will be found to lie side by side and more or less 
parallel to each other, whereas if the hand be now turned 
so that the palm is directed downwards it will be observed 



\ 



1 PUxor carpi raJialis. 

2 Prorufi'^r radii teres. 
\\ Bicipital fascia 

4 Olecranon process of ulna. 

5 hiternal condyle of humerus 

6 Triceps tendon. 
1 BraChialis aniictis. 

8 Triceps, inner head. 

9 TrKcps, long head. 



Delloid., F-xt. carpi vljtai 



Styloid process of ulna. 
Trapezius. 



; Postbordoful 
F'lexor c.t 
•' Palm. It 



Sterno-7nastoid. - - - , 

Hyoid done: 

Poinum Adamir-.. 
Pit of neck.. 
Clavicle., 
Breast bo7ic {sternum)., 
Pectoralis major . , 
Deltoid.,^ ~" 
Coraco-brachialis.^ ^~- 
Triceps, inner and lo7ig head. ^^^. 
' ' Biceps cubiti.^ \ ^-/'^ 
Brach. antic. \ 
Siipin.long.. \ \ 
Palm.long. '\ "\ 




PUxor carpi ulnar. 
F Uxor carpi radialis'. 

Pronator radii teres'. / .' 
Bicipital fascia', l 
fnUrnal cojidyle of humerus'. 

Iliac crest:'' 
Aponeurosis of external oblique.- - ' ' 
Tensor fasciae feniorisr' 
Ilio'psoas.- ' ' ' 

I^ectineusr'" 

Adductor longus: ' ' ' 

Rectus femorisr - - - 

Gracilis.-- - - 

Sartorius 

Semi tendinos. and ynembranosus.... 

Vastus inter mis.,. 

Band of J\ idler. ^ 

Rectus fern or is tendon . . 

Vastus internus. 

. , , , Patella. 
miernai candy le of femur 




" Bict 
, '-Ter.Vi 

' "Cor.-bra 
'~ ''Axilla. 
~Pector. ?naj 

Latis. dm 

-Pit of stoma 

^Digitations 

serratus m 

-•■Digitdtions c 

extern.obliq 

■'■''Rectus abdon, 
and 
Lineae trans 

'External obliq 

"Pliac crest. 

Ant.sup.il 

Gluteus me 

Pouparfs . 

""Troch.n 

Tensor ffi 

Gluteus VI 



' 'Sartorius 
-Vastus ex~ 
■Rectus fen 

'■Jlio-tibiaT 
Vastus ifiti 

■Bd of Rich 

Vastus exit 
•Rect.fem.tc 
Vastus int 
■•Ext.cond 
Pate 



Bones of Foi^e-arm 153 

that tlie outer bone of the fore-arm passes to lie obliquely 
across the inner bone. In the former position the limb is 
described as being siijpi7ie^ in the latter, ])rone. The move- 
ment whereby the limb is turned from the supine to the 
prone position is termed pronation^ the reverse action, viz. 
that which rotates the limb from the prone to the supine 
position, is called supination-, these movements will require to 
be studied in detail later, but it is necessary that they should 
be referred to here, in order that the student may under- 
stand the forms of the articular surfaces of the two bones. 

In comparing the two bones of the fore-arm it will be 
noticed that the upper extremity of the ulna is large, whilst 
its lower end is comparatively small. On the other hand, 
the upper end of the radius is small, whilst its inferior 
extremity is large and expanded. The student should 
associate with these details the fact that the ulna, or inner 
bone of the fore-arm, enters most largely into the formation 
of the elbow-joint, whilst the outer bone, or radius, plays 
the most important part in supporting the skeleton of the 
hand at the wrist-joint. 

As it is with the muscles which move the fore-arm on the 
upper arm that we are at present concerned, it will be ad- 
visable to consider first the form of the bone of the fore-arm, 
which is most intimately associated with these movements. 

The upper extremity of the ulna is large, and presents 
a very characteristic appearance. The most noticeable 
feature is a deep and well-marked notch, called the greater 
sigmoid notch, which lies between two prominent processes 
placed, one above, the other below it. The higher of these, 
called the olecranon process, lies in line with the upper end 
of the shaft. The posterior prominent angle of this process 
is a point of great importance, as it forms the tip of the 
elbow. 

The lower or coronoid process is a wedge-shaped piece of 
bone which is united to the front of the upper extremity 



154 Ulna 

of the shaft of the ulna, some little distance below the 
olecranon. The interval between the two processes corre- 
sponds to the notch already mentioned, and the surfaces 
of these processes, which bound the notch, are smooth and, 
in the living, coated with cartilage. If the ulna and the 
humerus are articulated, the surfaces of the greater sigmoid 
notch are seen to be admirably adapted to fit on the troch- 
lear surface of the lower end of the bone of the upper arm. 

A further examination of the upper end of the ulna 
reveals the fact that there is another articular surface to 
be studied in connexion with it. This is an oval hollow 
on the outer side of the coronoid process— called the lesser 
sigmoid notch — into which fits the thick margin of the 
rounded head of the upper end of the radius. 

The shaft of the ulna is long and tapering ; its upper 
part is prismatic on section, the various surfaces being 
separated by well-defined margins ; of these, one, called 
the posterior border, is highly important. This border, 
commencing above by the fusion of two lines which enclose 
between them a V-shaped area on the back of the 
olecranon process, may be traced down along the posterior 
aspect of the shaft towards the lower extremity, where 
it gradually fades away, corresponding, however, in line 
and direction with a projection to be hereafter described 
as the styloid process. The line so formed describes a 
sinuous curve and corresponds to a well-marked furrow on 
the back of the fore-arm, which is known by the name of 
the ulnar furrow. The importance of this border of the 
lx)no is due to the circumstance that throughout its entire 
length it is subcutaneous, a fact which the student can 
easily verify for himself by running his finger firmly along 
the back of the fore-arm, commencing above at the tip of 
the elbow, and ending below at the prominence on the back 
an.j innf-r side of the wrist which lies in a line with the 
little linger. 



Ulna 



155 



The lower end of the ulna, curiously enough called the 
head, consists of a rounded thick button-like process, fused 




Bones of rioflit fore-aim. 



Fia. 83. Front 
view. 



fiG. 84. Back 
view. 



Fig. 85. Outer 
side. 




/' 




h 



ry 



Fig. 86. Inner 
side. 



u. Ulna. 

a. Olecranon process of ulna. 

b. Coronoid process of ulua. 

c. Greater sigmoid notch. t 

d. Attachment of brachialis anticus, 

e. Triangular subcutaneous surface on 
• back of olecranon process. 

/. Styloid process of ulna." 

g. Posterior subcutaneous border of ulna. 



h. Lower end or head of ulna. 

r. Radius. 

I. Head of radius. 

j. Bicipital tuberosity to which is at- 
tached the tendon of the biceps. 

k. Placed near the insertion of the 
pronator radii teres. 

I. Expanded lowur end of radius, which 
articulates with the cdrpus. 



m. Styloid process of radius. 



on the extremity of the shaft. From the back and inner 
side of this head there projects downwards a prominent 
spur of bone called the styloid process of the ulna. The 



156 



Radius 



further details of this portion of the bone will be studied 
in connexion with the description of the wrist. 

The radius, or outer bone of the forcrarm, differs from the 
ulna or inner bone in being small above, and thick and 
expanded below. Moreover this bone is not as long as 
the ulna, which exceeds it by the length of the olecranon 
process. 

The upper end of the radius is called the head. It too 
may be compared to a thick disk-shaped piece of bone 
fixed on the end of the shaft. The upper surface of this 
disk or head is slightly hollow, so as to fit on to the 
smooth rounded surface of the capitellum or little head of 
the humerus. The circumference of the disk is thick and 
rounded, and on its inner side is adapted for articulation 
with the lesser sigmoid cavity of the ulna, which we have 
already seen on the outer side of the coronoid process of 
that bone. The head of the radius can be distinctly felt 
beneath the skin in the dimple or depression which appears 
behind and towards the outer side of the elbow, when 
the fore-arm is straightened on the upper arm. 

Below the head the shaft of the bone is constricted, but 
gradually expands as it passes downwards, becoming much 
thicker towards its lower extremity. About three-quarters 
of an inch below the head there is an outstanding osseous 
tubercle on the inner side of the shaft. This is called 
the bicipital tubercle, because the tendon of the biceps 
muscle is attached to it. 

The shaft of the bone is so overlain by muscles that 
it has no direct influence on the surface contours of the 
loro-anii, though indirectly it reacts on the surface forms 
l)y supporting these muscles, and thus gives rise to great 
modilications in the general outline of the limb, according 
a8 Its positiou is altered in the movements of pronation 
and Hupi nation already referred to. 

The lower on<l of the bone is broad and expanded. It 



Elbow-joint 157 

enters largely into the formation of the wrist-joint, furnish- 
ing by its inferior articular surface a broad support for the 
bones of the wrist. The external border of this expanded 
inferior extremity is prolonged downwards in the form of 
a blunt-pointed projection, called the styloid process of the 
radius. This process, as well as the bone immediately around 
it, is subcutaneous and forms the prominence on the outer 
side of the wrist which lies in line with the thumb. An- 
oval hollow, seen on the inner side of the expanded lower 
end of the bone, receives the thick margin of the rounded 
head of the ulna when the two bones are articulated. 

These points will require further consideration when the 
movements of pronation and supination are discussed and 
when the anatomy of the wrist is considered. 

There are few subjects which require more careful study 
than the elbow-joint. A knowledge of the shape and 
relations of the bones which enter into its formation is 
essential to enable the student to understand the alterations 
in form which depend on the movements of this joint. 

The elbow-joint is a typical example of a hinge-joint. 
That is to say, movement takes place in one or other of two 
directions, either forwards or backwards — such movements 
being tQrTaedi flexion and extension. In the former the fore- 
arm is bent forwards on the uppsr arm, in the latter the 
limb is straightened so that the fore-arm is brought 
nearly into line with the upper arm. The capsule which 
invests the joint is loose in front and behind, so as to 
allow freely of movements in those directions. At the sides 
of the joint, however, the capsule is strengthened by the 
addition of strong ligaments which prevent any lateral play. 

As has been already stated, the ulna is the bone of the 
fore-arm which enters most largely into the formation of 
this joint. The sigmoid notch between the coronoid and 
olecranon processes is fitted on to the trochlear surface of 
the humerus, but as this notch is less in extent than the 



1^8 



LfWtrenJ f/ulna. 



T<nd»m »f flexor 
nrfi Hinartl. 

1 /. tar/i ulma ru. 



ffui/rta//auia. • • 



Lo7vef f>!(£o 



Tendon 
carpi u. 



Tendon 

maris i 

hlexoi 

radi 

FUxof 
nine 



'rrmtitent/yU. • 
'I'f/i. inner 

a-kimlti 
■ •itMUl. • ■ - • • .-• 

■ 'tfi Itmtten • ■ '• 

'/<• .- 

'•rft.Umghtad. ..- 

JrmftUut. -• 

' '-nuU ^ 

i~»rat9-hta(hlatit ''' 
Itrti major . . . »'' 
ii/rm i/iHitrut 

fr-fftafit tfttt/fir. ■ •'' 

t'*m If K'nr hftumi ■ ' ' 

f*'loralx 
' ^'•inmii 4orit ■ •■ ' 

•'Sift ma^-HHt. -<* 
■t 0*liftH. -<r 

,•'»/. *** 

' lJ$Mt 
«/■...< ■ ■ * -.. 

Ctuhut „u.t,„, 



'/V»'»/«*#I • i, , 



■'fmieHfrmii 




Elbow-joint 



159 



surface on which it rests, it follows that, in the movements 
of the joint, the notch is applied to different parts of the 
trochlea as the forward and 
backward movements are per- 
formed. ThuSjWhen the limb 
is extended, i.e. straightened, 
the surfaces of the notch are 
in contact with the back and 
lower parts of the trochlea, 
whereas, when the elbow is 
forcibly bent, the notch is in 
contact with the anterior 
and inferior aspects of the 
trochlea. 

The processes, which bound 
the notch above and below, 
are prominent and outstand- 
ing, and some arrangement 
is necessary to prevent them 
unduly limiting the range 
of movement of the joint. 
Above the trochlear surface 
of the humerus, both in front 
and behind, the bone is 
hollowed out to form two 
fossae. That in front is 
called the coronoid fossa ; the 
one behind, the olecranon 
fossa. When the limb is ex- 
tended the anterior and upper 
border of the olecranon pro- 
cess lies in the olecranon fossa, 
whilst in the bent position 
the prominent lower border of the great sigmoid notch, 
formed by the coronoid process, occupies the coronoid fossa. 




Fig. 87. Front view of tbe elbow- 
joint. The head of the radius has 
been drawn away from the collar- 
like ligament {it which holds it in 
position. 

r. Radius. «. Ulna. 

a. Trochlear surface of humerus. 

b. Capitellum. 

c. Head of radius. 

d. Coronoid process of ulni. 

e. Internal condyle of humerus. 
/ Coronoid fossa of humerus. 

g. External condyle of humerus. 

fi. External lateral ligament. 

i. Oi bicular ligament. 

j. Leaser si<,'moid notch of ulna into 

whirb head of radius fits. 
k. Surface for the aitachnient of the 

brachialis anticus. 
I. Bicipital tuberosity of radius to which 

the tendon of biceps is attached. 



i6o Elbow-joint 

The movements of flexion and extension of the fore-arm 
are effected by the sigmoid notch being drawn over the 
trochlea of the humerus, but as the radius is united to 
the ulna by means of certain joints it follows that as the 
ulna moves it carries with it the radius. It has been already 
stated that the upper surface of the head of the radius is 
hollowed out to adapt it to fit the capitellum or small head 
of the humerus, but as this latter articular surface is placed 
more on the front, than on the lower aspect of the inferior 
extremity of the humerus, it results that the radius is but 
slightly in contact with this surface of the humerus when 
the limb is fully extended. When the elbow is bent, how- 
ever, the head of the radius is more closely applied to the 
capitellum. The surfaces just described are so arranged 
as to permit not only of movements in a backward and 
forward direction, but also of movements of rotation of the 
head of the radius on the capitellum. This movement of 
the radius is possible in all positions of the limb, but is 
best controlled and most efficiently employed when the 
elbow is bent, for under these conditions the head of the 
radius fits more accurately on the capitellum and is there- 
fore better supported. 

These facts are borne out by experience. It is in the 
movements of pronation and supination, already incident- 
ally referred to, that the rotation of the head of the 
rafiius takes place. When we make use of these move- 
ments, and desire to employ a considerable amount of 
force, wo are accustomed to do so with the arm bent, as 
in the acts of inserting a corkscrew or using a screw- 
drivor, inr in tins position of the limb the head of the 
radius is well supported by the capitellum. But, whilst 
this is the case, the student must not overlook the fact 
that the same movements may be performed with the 
limb extended, as in fencing, or when we lift and twist 
anything a})Out ; ii, ilio latter act, however, it will be 



Elbow-joint i6i 

obvious that the joint is subjected to a tearing rather than 
a crushing strain. 

It is necessary to consider the movements of flexion and 
extension of the elbow more carefully. Were the move- 
ments as simple as have been described, one would naturally 
expect that when the fore-arm is bent on the upper arm 
the anterior surfaces of the two parts of the limb would be 
brought into contact ; that this is not the case, the student 
can easily demonstrate for himself. If the arms be extended 
by the sides of the trunk with the palms of the hands 
directed forwards, and the fore-arms be then bent upwards 
without any conscious restraint, the elbows being still kept 
in contact with the sides of the chest, it will be found that 
the hands will fall naturally in a crossed position on the 
front of the breast, and not, as one might reasonably expect, 
over the shoulders of the corresponding limbs. This will 
be obvious if the attempt is made to touch the shoulder 
with the hand of the same side, while the upper arm is 
still closely applied to the side of the body : the effort will 
prove that the action is a very constrained one. 

If the arms be again extended by the side, in the manner 
above described, i. e. with the palms directed forwards, 
another point will be noticed. The fore-arms appear 
splayed on the upper arms ; in other words, the axis of the 
fore- arm when viewed from the front is not in line with 
the axis of the upper arm, but forms with it an obtuse 
angle. Why this is not as a rule apparent is due to the 
fact that when we carry our limbs by the sides of our body 
we usually have the palms of the hands directed inwards 
towards the sides of the thighs, as in the military position 
of attention ; in this attitude the bones of the fore-arm are 
in a state midway between supination and pronation, 
a position which so modifies the direction of the axis of 
the fore-arm as to bring it directly in line with the axis 
of the upper arm, and thus cause the disappearance of the 

THOMSON ]^ 




I ^ U ! I U : : 



I ///// 



'^ V t i t i - 
■<, «^ <«i K k.< 



Elbow-joint 



163 



obtuse angle alluded to. To represent this angle has been 
regarded by many as offensive and inartistic; at the same 
time it must be borne in mind that the condition is 
a perfectly natural one, and the action in which it is most 
pronounced is by no means unfrequently employed by 
many as a gesture which is usually associated with an 
obsequious manner. 

The explanation of the above facts is to be found in the 
form of the articular surfaces by which the humerus and 




~~a 




Fig. 88. Diagram to illustrate the manneEjin which flexion of the 
elbow affects the limb. 



a a. The axis of rotation of the joint 
is placed obliquely to the long 
axis of the humerus. 

c c and d d. EejBresent two pieces of 



wood hinged together obliquely 
at b b. When d d is bent upon 
c c it occupies the position re- 
presented by the dotted lines e e. 



ulna are united. The student will best understand this by 
a reference to the accompanying diagrams (Fig. 88). These 
do not account for all the movements which take place at 
the elbow, but they at least render clear the cause of the 
obtuse angle when the limb is extended and the crossing 
inwards when the fore-arm is bent. As will be seen, this 
is due to the fact that the axis of rotation of the hinge is 
not placed at right angles to the axis of the upper segment 
of the limb, but obliquely to it. The dotted line in the 

M 2 



164 Elbow-joint 

fio-ure represents the position which the lower segment of 
the two hinged pieces would occupy if it was bent on 
the upper. 

The influence of the bones of the elbow-joint on the 
surface forms must now be studied. Of the two condyles 
of the humerus the internal is the more prominent, and 
can be readily felt and seen on the inner side of the elbow. 
The external, not nearly so pronounced on the bone, can be 
felt from the surface, but causes no corresponding projection, 
because the muscles which rise from the ridge leading to • 
it are so fleshy as completely to mask its form (Pis., pp. 170, 
200). Its position, however, is clearly indicated by an inter- 
muscular furrow which lies behind and to the outer side of 
the elbow between the muscles already spoken of and others 
which rise from the back of the external condyloid process. 
This furrow in the muscular male is clearly defined by the 
margin of the outstanding muscles on either side, but in the 
female and child, owing to the larger quantity of sub- 
cutaneous fat, it is replaced by a dimple (PL, p. 262). If the 
finger be placed in the upper part of this furrow the back of 
tlio external condyle can be distinctly felt, whilst imme- 
diately below it the finger will readily recognize the head 
of the radius (Pis., pp. 50, 162, 200). _ 

The olecranon process of the ulna is a feature of great 1 
importance in connexion with the surface forms of the 
elbow, a circumstance due, not only to its prominence, but § 
also to its mobility. The projection of the hinder and 
upper part of this process forms the tip of the elbow. 
Wlion the arm is fully extended this point of the bone lies 
on a level with a line, drawn across the back of the joint, 
connecting the two condyloid processes. When the arm 
18 bont, the tip of the elbow becomes more prominent and 
(h'Hconds to a much lower level. In the position of the 
hmb in which the fore-arm is flexed on the upper arm at 
a right angle, the tip of the olecranon lies in direct line with 



Elbow-joint 



165 



the axis of the humerus, and from an inch to an inch and 
a half, according to the size of the bones^ below the level of 
the internal condyle. These points, if viewed from behind 
with the arm in this position (Fig. 91), will be seen to form 
a triangle, of which the base corresponds to an imaginary 
line connecting the two condyloid processes of the humerus, 
the apex being formed by the tip of the olecranon. 

If flexion of the fore-arm be carried to a greater extent, 






Fig. 89. As seen 
from the front when 
the joint is extended. 



Bones of the left elbow. 

Fig. 90. As seen 
from behind when the 
joint is extended. 



Fig. 91. As seen 
from behind when the 
joint is bent to a right 
ans^le. 



e. External condyle. 



». Internal condyle. 



the tip of the olecranon will advance further, and the outline 
of this process will be rendered more distinct. 

The back of the olecranon process forms a triangular 
surface which is bounded on either side by bony ridges : 
these gradually coalesce inferiorly to form the posterior 
border of the shaft of the ulna. The triangular surface 
of bone included between the two lines is uncovered by 
muscle and immediately underlies the skin ; it can be 



i66 



Elbow-joint 




Fig. 92. View of the bones of the right elbow from the outer side 
with the joint extended. 




Fio. 93. View of the bones of the right elbow from the outer side 
with the joint slightly bent. 




Fio. 94. View of the bones of the right elbow from the outer side 
witli tlie joint still further bent. 



A. lluiiioiuu. 
c. Cupitulluiu uf bumurus. 



r. Kudius. u. Ulna. 

0. Olucranon proooss of ulna, 



Fascia of Upper Arm 167 

easily felt, and i^ limited above by the pointed extremity 
of the olecranon, whilst below it becomes continuous with 
the ulnar furrow which corresponds, on the surface, to the 
posterior border of the ulna. 

The movements of which the elbow-joint is capable are 
those of flexion and extension. The former is effected by 
the contraction of the muscles of the front of the upper arm. 
and is checked by the opposition of the soft parts which 
clothe the anterior aspect of the limb. Extension is due 
to the contraction of the triceps, a muscle lying on the 
back of the upper arm, and is limited by the tightening 
of certain ligaments and the mechanical locking of the 
bones, especially when the action is a violent one. The 
extent to which this movement may take place varies in 
different individuals ; in "some, owing to a greater laxity of 
the ligaments and to modifications in the form of the bones, 
a certain amount of hyper-extension is possible. This gives 
rise to an unpleasant appearance, for the fore-arm appears 
as if bent back on the upper arm. 

The muscles which control the movements of the elbow- 
joint must now be described ; they form the fleshy masses 
on the front and back of the upper arm. Beneath the 
skin and subcutaneous fat of the arm a sheath of fascia 
invests the entire limb. This fascial sheath may be com- 
pared to a tight-fitting sleeve. Above^, it is continuous 
with the fascia covering the shoulder and the layer which 
forms the floor of the armpit ; at several points corre- 
sponding to the attachment of the muscles which form 
the anterior and posterior folds af the armpit, it receives 
considerable additions by means of fibrous strands derived 
from the tendons of insertion of these muscles. These 
fibrous bands mask to some extent the borders of the 
tendons of insertion of these muscles, and render more 
flowing the outline of the axillary folds, where they become 
blended with the surface contours of the upper arm. 



j58 Brachialis anticus 

A closer inspection of tins fibrous slieatl^ reveals the fact 
that in the upper arm it is subdivided by partitions, which 
pass from it, one on either side, to become attached to the 
rido-es of bone which have been already seen to extend 
upwards on each side of the shaft of the humerus from the 
internal and external condyloid processes. 

These partitions are called the intermuscular septa, 
internal and external, according as they lie along the inner 
or outer side of the limb. The result of this arrangement 
is that the sleeve or sheath is divided into two compart- 
ments, in the anterior of which are lodged the muscles 
which bend the elbow, and which are known as the flexor 
group, whilst occupying the posterior compartment is the 
extensor mass. The intermuscular septa are structures of 
some importance as determinants of surface forms, but 
their influence in this respect will be better studied when 
the actions of the various muscles have been considered. 

Of the flexors of the fore-arm there are two which may 
now be conveniently studied. There are other muscles which 
assist in performing these movements, but the description 
of them is for the time delayed. The two referred to are 
the brachialis anticus and the hiceps of the arm. 

The hracliialis anticus is the deeper as well as the smaller ; 
it passes directly over the front of the elbow-joint, arising 
from the humerus above and passing to the ulna below. It 
takes origin from the front of the lower half of the shaft 
of the humerus, as well as from the intermuscular septa, 
more particularly that on the inner side ; superiorly its 
fibres lie on either side of the insertion of the deltoid. 
rhf) fleshy fibres of the muscle diverge above, but converge 
below towards the insertion, vv^hich is into the front of the 
coronoid process of the ulna. The widest part of the muscle 
lies at some little distance above the elbow. 

The brachialis anticus is overlain by the biceps muscle, 
but as the latter is narrower than the former the fibres of 



I 



Biceps cubiti 169 

the bracliialis are exposed, both on the inner and outer 
aspects of the front of the limb. Along the outer side of 
the Tipper arm the fibres of the brachialis are seen lying 
in the interval between the biceps in front, the external 
intermuscular septum and the outer head of the triceps 
behind, the insertion of the deltoid above, and the origin of 
a muscle called the supinator longus below (Pis., pp. 38, 58, 
62, 104, 126, 148, 152, 162, 170, 182, 200, 382, 434). Along 
the inner aspect of the upper arm the fibres are visible 
between the biceps in front, the internal intermuscular 
septum and inner head of the triceps behind, and the 
origin of the pronator radii teres muscle below (Pis., 
pp. 44, 158, 162, 170, 176, 182, 212, 434). In both these 
situations the muscle is superficial, and, during powerful 
contraction, may directly influence the surface forms. In 
action it will also push forward the lower part of the biceps, 
which lies upon it, and so indirectly exert an influence on 
the superficial contours. 

The muscle acts as a flexor of the fore-arm ; by its in- 
sertion into the coronoid process of the ulna it draws 
the sigmoid articular area over the trochlear surface of the 
humerus. 

The hiceps flexor cuhiti, or biceps of the arm, belongs to 
that group of muscles which has been described as indirect 
in their action. Under normal conditions it has no attach- 
ment to the humerus whatever, but arises from the shoulder- 
blade. This it does by two tendons, one of which, called 
the long head, springs from the blade-bone just above the 
articular surface (glenoid fossa) for the head of the humerus ; 
the other, or sJiort head, arises along with the coraco- 
brachialis (as has been already described at the beginning 
of this chapter) from the coracoid process of the shoulder- 
blade. 

These tendons lie under cover of the muscles which form 
the cap of the shoulder, and it is just before they appear 



lyo 




a. Pectoralii uiajjr. 

b. l.alisiiwus liorsi. 
(. Teres ma/or. 

d. Cora, o hracltialii. 

e. Deltoiti. 

/. Triceps, lou^ head. 

^. Triceps, inner head, 

h. Btctps c libit i. 



i. Intel :ial iuley'/iHiCular septum. 

;. Bnxchialis antuits. 

k. Internal condyle of humerus. 

I. Bicipital J a scia. 

m. Pronator radii teres, 

71. r.xlensor carpi radialis longior. 

o. Siipinatoj- lonnits. 

p. l-te.\oy carpi radialis. 




MIDWAY I'.KTWKKN THE PRONE AND SUPINE POSITIONS 



y. T.xtensor carpi radialis brevior. 
r. I'ahnaris lonf;us. 
J. lendom oj radial extensors. 
I. t otnmoH extensor a/ fingers. 
I J-xleuior ositt tnelacarpt pollicis. 
i l-xttUior pritni lulernodii pollicis. 
V, l:xleuior ieiiindi inlernodii potlun. 



7u, Annular ligament o/ivrist. 

X. Palmar fascia, 

y. Flexor carpi ulnar is. 

z. Flexor sublimit digitoriun. 

1. Triceps tendon. 

2. Olecranon process of ulna. 

3. Styloid process 0/ ulna. 




Biceps cubiti 171 

beneath the anterior fold of the armpit that they become 
fleshy. Each tendon is provided with a belly, hence the 
name of the muscle, but these bellies are so closely applied 
the one to the other that we may disregard their separate 
existence and consider only their combined fleshy mass 

(Fig. 79^ P- 147)- 
At the upper part of the limb this appears as it escapes 

below the margin of the pectoralis major, which here forms 
the anterior fold of the armpit ; gradually increasing in 
bulk, the muscle attains its maximum thickness about the 
middle of the upper arm. Below this point the fibres are 
gathered together to end in a powerful tendon, part of 
which passes by a ribbon-like expansion to be inserted into 
and blended with the fascia of the fore-arm which over- 
lies the muscles which spring from the inner condyle of 
the humerus. The remainder, by far the stronger portion, is 
continued downwards as a thick rounded tendon, which is 
inserted into the bicipital tubercle of the outer bone of the 
fore-arm (radius). In form the muscle may vary consider- 
ably in different individuals, a difference not dependent 
on its development from exercise or otherwise, but due 
to the arrangement of its component parts. Thus in some 
the muscular fibres are long and the tendinous portions 
are relatively short, whilst in others the fleshy belly of the 
muscle is short and the tendons are long. The influence 
of these varieties of the muscle on the surface form may 
be better understood by a reference to the condition met 
with in the calf of the leg. It is a matter of common 
knowledge that the form of the leg differs much in different 
persons ; in many the prominence of the calf is situated 
high up on the back of the leg, whereas in others the 
swelling of the calf reaches lower down and imparts a much 
more clumsy appearance to the ankle. This is entirely due 
to differences in the length of the fleshy bellies of the 
muscles which are placed on the back of the leg. 



172 



Biceps cubiti 



lu considering the relations of the biceps to the surface 
the student must bear in mind that the muscle is in 
great part superficial. It is only at its upper and lower 
attachments that it is concealed from view. Above, the 
anterior fold of the armpit covers the tendons of origin 
of the muscle. Below, the tendon of insertion sinks deeply 
between the muscles of the fore-arm (Pis., pp. 58, 62, 72, 86, 
126, 148, 152, 158, 17c, 176, 182, 200, 212, 382, 434). 

The greater part of the fleshy belly of the muscle is 
therefore superficial, and it is to this that the rounded 
form of the front of the upper arm is due. The form of 
the belly of the muscle is such that its thickness is greater 
than its width ; hence the diameter of the upper arm is 
greater from before backwards than from side to side. As 
has been already said, the width of the belly of the biceps 
is not sufficient to conceal entirely the brachialis anticus on 
which it rests, so that a portion of the latter muscle is 
exposed on either side of it (Pis., pp. 72, 170). 

The outer and inner borders of the biceps are defined 
by two shallow furrows which run down one on either side 
of the front of the upper arm. The outer furrow corre- 
sponds superiorly to the interval between the deltoid and 
biceps, whilst below, where it is usually well marked, it 
overlies the interval between the biceps above and to the 
inner side, and the supinator longus below and to the outer 
side. The middle part of this furrow, which is less well 
marked, overlies the external intermuscular septum, and it 
is hero that fibres of the brachialis anticus are brought into 
direct relation with the surface (see ante). These facts will 
bo clearly demonstrated by a reference to Pis., pp. 58, 62, 

72, 148, 170, 176, 182, 212, 216. 

Tho surface i arrow along the inner side of the upper arm 
corresponds to the inner border of tho biceps muscle. 
Above, it may bo traced into tho hollow of the armpit, 
though in certain positions of tho limb, viz. when the arm 



Biceps cubit i 173 

is uplifted, the prominence due to the coraco-brachialis will 
interrupt it to some extent. The bottom of this furrow 
corresponds to the brachialis anticus muscle and the internal 
intermuscular septum, whilst the posterior margin of the 
furrow is due to the prominence of the triceps muscle on 
the back of the arm. Below, it blends with the surface in 
front of the elbow. The aponeurotic insertion of the biceps 
into the fascia of the fore- arm bridges across the interval 
which would otherwise exist between the biceps and the 
muscles of the fore-arm arising from the internal condyle 
of the humerus. The furrow along the inner side of the 
upper arm is much less marked than what we would expect 
from a study of the muscles alone, because the great blood- 
vessels and nerves which supply the arm lie along the limb in 
this situation (Pis., pp. 148, 152, 170, 176, 182, 212). 

The biceps muscle, from its connexion with the radius, acts 
as a powerful flexor of the fore-arm, but it also assists in 
raising the arm at the shoulder-joint, as it derives its 
origin from the shoulder-blade. Its action as a flexor of 
the fore-arm is modified by the position of the radius at 
the commencement of the act ; for if the radius, which 
is the bone principally concerned in the movements of 
pronation and supination, be crossed over the ulna or inner 
bone of the fore-arm, as in the prone position, the first 
effect of the contraction of the biceps will be to supinate 
the limb. The muscle is therefore a powerful supinator 
as well as a fiexor of the fore-arm. The action of the biceps 
as a supinator may be easily demonstrated as follows: — 
Bend the elbow until the fore arm forms a right angle with 
the upper arm, then rotate the bones of the fore-arm in 
such a way as to direct the palm of the hand upwards and 
downwards, or backwards and forwards, as the case may 
be. The biceps will be most powerfully contracted when 
the limb is in the supine position, i. e. with the palm of the 
hand upwards, much less so when in the prone position. 



I y^ Triceps 

The fleshy mass which is placed on the back of the upper 
arm acts as an extensor muscle of the fore-arm : it is 
called the triceps^ and, as its name implies, arises by three 
heads, which are distinguished as the inner, the outer, and 
the middle or long head. The two former arise from the 
humerus ; the latter springs from the outer margin of the 
blade-bone, just below the shallow socket which receives 
the head of the humerus (Pis., pp. 38, 44, 50, 52, 94, 98, 104, 
126, 158, 162, 176, 182, 200, 212, 382). These three fleshy 
masses are attached inferiorly to an aponeurotic tendon, from 
an inch to an inch and a half wide, which reaches as high as 
the middle of the back of the upper arm. By means of this 
tendon the muscle is inserted into the hinder part and outer 
border of the olecranon process, a few of the fleshy fibres of 
the inner head of the muscle being directly connected with 
the olecranon without the intervention of tendinous fibres. 
As the fleshy mass of the muscle overlies the back of the shaft 
of the humerus, it is brought into relation with the inter- 
muscular septa which have been already described. From 
the posterior sarface of these septa the outer and inner 
heads of the muscle derive fibres of origin. It will thus be 
Reen that these, septa lie between the brachialis anticus 
muscle in front and the triceps muscle on the back of the 
upper arm, one septum along the inner, the other along 
the outer side of the limb. 

The triceps is superficial except at the upper part of the 
limb, whore the deltoid covers a part of the long head as 
well as the highest attachment of the outer head. 

The surface contours of the back of the upper arm depend 
on the arrangement of the fibres of the triceps, and the 
distinction between its several parts is most apparent when 
the muscle is in a state of powerful contraction. In this 
condition the contrast between the fleshy and tendinous 
parts of the muscle is at once apparent. The area overlying 
the tendinous part forms an elongated flattened surface, 



Anconeus 175 

passing up the centre of the back of the limb from the tip 
of the elbow below to a point above corresponding pretty 
closely to the middle of the length of the upper arm. On 
either side of and above this flattened area, the bulging 
produced by the contraction of the fleshy fibres is seen. 
The most noticeable contour is that caused by the attach- 
ment of the outer head of the muscle to the tendinous part ; 
this forms a well-marked oblique furrow, which repeats 
at a lower level that due to the hinder border of the 
deltoid as it passes across the upper part of the limb 
(Pis., pp. 50, 104, 122, 162, 200, 212). 

On the inner side of the limb, separation of the long 
from the inner head is indicated by a furrow which passes 
obliquely downwards and backwards across the hinder and 
inner aspect of the upper arm from a point about its middle 
towards the inner border of the tendinous part of the muscle 
(Pis., pp. 44, 162, 176, 212). 

The muscle acts as a powerful extensor of the fore-arm 
on the upper arm. Owing to the attachment of the long 
head to the blade-bone, this part of the muscle also assists 
in drawing down the elevated limb. 

Mention may now be made of a muscle called the anconeus, 
which, whilst it might well be described with the muscles 
of the back of the fore-arm, is better considered here, as it is 
intimately associated with the triceps. 

The anconeus has a triangular outline, and fills up the 
interval between the back of the external condyle, the outer 
border of the olecranon process, and the upper part of the 
shaft of the ulna. It thus overlies to a slight extent the 
back of the head of the radius. The muscle arises from 
the posterior surface of the external condyle of the humerus 
by a pointed tendinous attachment. The fibres spread out 
in a fan-shaped manner ; the upper, almost horizontal, cross 
inwards to be attached to the outer margin of the olecranon, 
whilst the lower pass, with varying degrees of obliquity, to 



]76 External Intermiiscvtlar Septimi 

be inserted into the posterior border of the ulna along its 
outer margin. The extent of this attachment varies some- 
what, but, generally speaking, may be said to correspond to 
the upper third or fourth of the length of the bone. 

The muscle is held down by an expansion derived from 
the outer side of the tendinous insertion of the triceps. At 
its origin the anconeus is directly related to the muscles 
which arise from the front and outer side of the external 
condyle, and the interval between it and these muscles 
corresponds to the depression to which attention has already 
been directed in considering the surface relations of the 
parts about the elbow. 

The general lie of the muscle may best be understood by 
a reference to Pis., pp. 50, 52, 162, 176, 200, 212. It acts, 
along with the triceps, in extending the fore-arm. 

The influence of the foregoing muscles on the surface 
form of the limb has been already considered, but reference 
may now be made to the intermuscular septa which have 
been previously described. Of these the more important, as 
a determinant of surface form, is the external. When the 
muscles are powerfully contracted and the limb is flexed, 
the margin of the external septum forms a well-defined 
ridge, which passes up from the external condyloid process. 
An important group of muscles, which will be described 
in the next chapter, arises from the front of this septum as 
well as from the front of the external condyle. When the 
limb is straight these muscles overlie the condyle and so 
fwirtially mask its form, but with the elbow bent and the 
muscles powerfully contracted the condyle is uncovered 
and the attachment of the external intermuscular septum 
to it is more plainly seen, as is shown in Pis., pp. 176, 182, 
212. In this position the surface ridge, corresponding to 
the sharp edge of the septum, lies between the external 
head of tlio triceps and the muscles of the fore-arm which 
arise irom its anterior surface. 



d 



Internal Intermuscular Septum 177 

The internal intermuscular septum does not produce so 
pronounced a surface elevation, but its position may be 
readily recognized on the inner side of the upper arm when 
the elbow is bent and the muscles are powerfully contracted. 
Under these conditions it may be traced upwards from the 
prominent internal condyle as a rounded elevation which 
separates the triceps behind from the brachialis anticus in 
front (Pis., pp. 44, 152., 162, 176, 182, 212). 



N 



CHAPTER VII 



THE FORE-AEM 



As has been already pointed out, the two bones which 
form the skeleton of the fore-arm are jointed together in 
a manner different from that of the corresponding bones of 
the lower limb. In the leg, the bones are bound together in 
such a way that they cannot possibly move on one another, 
whilst in the fore-arm they are united so that one of 
them may rotate round the other. The importance of this 
arrangement cannot be overlooked when we consider how 
much this movement enhances the utility of the hand. 
By its means we are enabled to perform such acts as in- 
serting a corkscrew or turning a screw-driver : it permits 
us with ease to make use of any screwing action of the 
hand. We employ it every time we turn the handle of 
a door. 

These movements are termed p7'0?iation and supination. 

Let us endeavour to analyse them in their simplest form. 
With the elbow by the side, and the fore-arm bent on the 
upper arm at a right angle, we €an control the movement 
of the hand so that the palm is directed upwards. In 
this condition the limb is said to be supine. A careful 
examination of the limb in this position will reveal the 
fact that the two bones of the fore-arm are lying side by 
side, tlie radius externally, the ulna internally. The form 
of the fore-arm is such that it is thicker from side to side 
than from before backwards. Whilst still retaining the 
r-lbow by the side, the hand may be turned so that the palm 
IS directed downwards ; the limb is now placed in the prone 
position, performing at the same time the movement of 



Pronation and Supination 179 

pronation. Coincident with this change in the position 
of the palm some remarkable alterations in the arrange- 
ment of the parts of the fore-arm are to be noted. The 
bones no longer lie side by side, since the outer bone or 
radius is now directed obliquel}^ across the front of the 
ulna or inner bone. The head of the radius still retains 
its relation to the outer side of the upper extremity of the 
ulna, but the lower end of the radius is placed to the inner 
side of the lower extremity of the ulna. The shaft of the 
radius therefore passes obliquely across the front of the 
shaft of the ulna. As has been stated in the previous 
chapter, the lower end of the radius is large compared 
with that of the ulna. As a consequence of this it enters 
more extensively into the formation of the wrist-joint, and, 
playing as it does so important a part in the formation 
of the joint by means of which the hand is articulated 
with the fore-arm, it follows that when the radius moves 
it carries with it the hand. Now when the radius is lying 
parallel to and along the outer side of the ulna the palm 
of the hand is directed upwards and the thumb lies to 
the outer side ; but when the radius has moved so as to lie 
obliquely across the front of the ulna it causes the hand 
to turn, so that the palm is directed downwards and the 
thumb inwards. 

This change in the position of the radius is associated 
with marked alterations in the form of the fore -arm. As 
we have already seen, Ihe greatest thickness of the limb 
with the hand in the supine position is from side to side. 
When however the radius lies across the front of the ulna, 
the flatness of the front of the fore-arm disappears, and the 
greatest thickness of the limb is now from front to back. 
This alteration in form is primarily due to the change 
in the relative position of the bones, but as the radius is 
covered by the powerful muscles which form the fleshy 
mass along the outer side of the fore-arm, it results that 

II 2 



i8o Pronation and Supination 

when this bone changes its position it carries them with 
it, and thus brings about a further modification of the 
surface forms. 

When the limb is in the prone position, i. e. with the palm 
directed downwards, we can reverse the action and bring the 
palm upwards again. This is the movement of supination. 

Pronation and supination, therefore, are movements 
whereby we may rotate the axis of the hand through an 
arc of I8o^ or about half a circle. ' 

J3ut if the student will repeat the movement already 
described/ and, in addition, will now extend the elbow, 
the palm of the hand, which was in the first instance 
directed downwards, will, now the limb is straightened by 
the side of the body, be directed backwards. In the first 
position we had no further power of rotating the hand, 
but when the axis of the fore-arm is brought into line 
with the axis of the upper arm the hand can be turned 
further round, so that the palm is directed outwards. 
There is thus a considerable gain, for, whilst we were only 
able to rotate the hand through i8o° with the elbow bent, 
now that the limb is straightened we can rotate the hand 
to the extent of 270°, i. e. through three-quarters of a circle. 
The explanation of this difference is simple. Superadded 
to the movements of pronation and supination, move- 
ments which are confined to the fore-arm, there is the 
iurthor advantage of bringing into play the power of 
rotation at the shoulder-joint; this enables us to turn 
the humerus, and the bones of the fore-arm along with it, 
aii'l so loads to a rotation of the entire limb. 

These two movements must be kept quite distinct in the 
mind of the student, as well as the fact that they can only 
bo associated when the limb is straight, i. e. with the elbow 
oxtendr'd. The best example of this combination of the 
two actions is seen in certain of the thrusting and parrying 
movements in fencing. 



\ 



Pronation and Supination 



i8i 



Confining our attention strictly to the movements of 
pronation and supination, it is necessary to study tlie 
mechanism by which they 
are effected. 

As will be remembered 
from the description given 
in the previous chapter, the 
)i^ad of the radius is like a 
thick disk of bone united to 
the upper extremity of the 
shaft. The margin of this 
disk is coated with articular 
cartilage, and fits into the 
oval hollow on the outer side 
of the coronoid process of the 
ulna, called the lesser sigmoid 
notch, where it is held in 
position by a collar or band, 
called the orbicular ligament 
(Fig. 95). This ligament, 
whilst it does not interfere 
with the rotation of the head 
of the radius within it, serves 
to retain the head of the bone 
in contact with the articular 
surface of the lesser sigmoid 
notch. Another important 
point to remember is that 
the external lateral ligament 
of the elbow-joint, instead 
of being connected with the 
head of the radius, is attached 
to the orbicular ligament, so 

that the rotation of the radius at this joint is in no way 
interfered with. These points are better shown in the 




Fig. 95. A view of the bones of 
the right elbow with the head of the 
radius witlidrawn from the lesser 
sigmoid notch and the orbicular 
ligament. 

a. Trochlear surface of humerus. 
h. Capitellum. 

c. Head of radius. 

d. Coronoid process of ulna. 

e. Internal condyle of humerus, 
/. Coronoid fossa of humerus. 

g. External condyle of humerus. 

h. External lateral ligament of elbow. 

i. Orbicular ligament. 

j. Lesser sigmoid notch. 

k. Surface of attachment of brachialis 

anticus. 
I. Bicipital tubercle of radius. 
r. Radius. 
u. Ulna. 



l82 



^'/v oj yil ctnfcal vertebra 
Trapatui , 

Airmnion procesi 



Spia* of uapula 

Ekiloid 

Jn/ro-spiitatus 
Rhomb maj 



Jiead of ulua 

.Ext.sccniidi 
interiiod.poi 



Extensors of tfmmb 

Ext. comjiigitoniiii 

Ext.carp.rcut 

brevior. 

^xt. car p. nil 
Aiicoiieits. 




itiflotd prwtti 

of ulma ■ 

ClmlfHt maiimms 
Jlt»-tt6iaJ banJ 



Olecranon 

\ ExI. carp rad. long. 

Supinator longus. 

• Bracliialis anticu c. 

Biceps cnbiti. 

■Triceps, outer head. 

■ ■ Triceps, long liead- 
Deltoid 

■ ■ ■ ylcromion process 
■ Teres major 

■ ■■■ Spine of scapula 

/nfrarspiuatus. 

Rltoniboideus major. 

7 rapezius. 
Lalissimus dorsi. 



Iliac crest 



Posterior superior iliac spme. 

Gluteus medius. 

Posterior surface of sac r ton. 

Gluteus tnaxiniMS 

Trochanter major 
Tensor fasciae femorit. 



Ilichtibial b.iud. 



Pronation and Supination 183 

illustrations, the first of which (Fig. 95) shows the bones 
of the elbow-joint, with the head of the radius withdrawn 
from the orbicular ligament and lesser sigmoid notch. Fig. 
96 (i.) represents a section through the upper ends of the 
bones of the fore-arm, and shows how the head of the radius 
is surrounded by the orbicular ligament. 

Turning to the lower ends of the bones, we note first the 
fact that the lower extremity of the radius is much larger 
than the lower end (or head) of the ulna. On that side 
of the enlarged extremity of the radius which is directed 
towards the head of the ulna we observe a hollow articular 
surface, called the sigmoid cavity of the radius, in which the 
head of the ulna rests. In this respect, therefore, there 
is a striking similarity between this joint and the articula- 
tion between the upper extremities of the bones. In the 
one case the head of the radius fits into the lesser sigmoid 
hollow of the ulna, in the other the head of the ulna fits into 
the sigmoid hollow of the lower end of the radius, but the 
manner in which the ligaments unite the ends of the bones 
is quite different. The lower end of the ulna is not bound 
to the radius by an orbicular ligament, but by a triangular 
fibro-cartilage, the apex of which is attached to the base of 
the process of bone which springs from the inner and hinder 
aspect of the head of the ulna, a process which has been 
already referred to under the name of the styloid process. 
By its base the fibro-cartilage is united to the ridge on 
the lower end of the radius which separates the articular 
surface for the ulna from that for the bones of the wrist. 
This arrangement permits of an entirely different kind 
of movement from that described in connexion with the 
superior joint. The head of the ulna does not rotate within 
the sigmoid hollow of the radius, as does the head of the 
radius within the orbicular or collar-like ligament, but 
the lower end of the radius travels over and round the 
head of the ulna, so that \\& position may be altered from 



i84 



Pronation and Supination 



a condition in wliich it lies to the outer side of the ulna 
to one in which it comes to be placed to the inner side 
of the same bone. 

The accompanying diagrams (Fig. 96, 11. and iii.) will 
perhaps enable the student to understand this point. The 
lower ends of the two bones are represented at (11.) in the 
supine position: the radius here lies to the outer side of 
the ulna ; at (iii.) the same bones are represented in the 



I. 



II. 



III. 




Fig. 96. Diagrams to illustrate the movements of the radius and 
ulna during pronation and supination. 
A section across the upper ends of the II. In supination. 



lionos oi' the right limb, as seen ft-ora 
iibove. 

a. Ulna. 

b. Head of radius retained in 
r. The lessor sipfnioid notch by 

d. The orbicular ligament. The head 
of the radius h can rotate in 
either direction within the collar 
formed by d. 

IL and III. represent the relations of 
the lower ends of the bones of tho 
right limb, as seen from above. 



III. In pronation. 

a. Lower end of ulna (head). 

6. Lower end of i*adius. 

/. Triangular fibro-cartilage attached 

to 
y. The styloid process of ulna. Tho 

arrows show the directions in 

which the radius may move on 

the ulna. 



prone position — the arrows indicate the direction in which 
the radius may move from either extreme. At the same 
time that this movement is taking place the lower end of 
tho ulna undergoes slight lateral displacement. But it is 
hardly necessary here to enter into a detailed account of the 
complex nature of this latter movement ; the points to be 
emphasized are these, viz. that the upper end of the radius, 
wliilst it undergoes a rotatory movement, still retains its 
rolativo position to the ulna and humerus, whereas the move- 



Pronation and Supination 



185 



ment of the lower end of the radius effects a change in its 
position from the outer to the inner side of the uhia. It 
follows, therefore, since the shaft 
of the radius connects the two 
extremities, that when these two 
extremities are both lying to the 
outer side of the ulna the shaft of 
the radius will also lie to the outer 
side of the ulnar shaft. As we 
have seen, the head of the radius 
always lies to the outer side of 
the superior extremity of the ulna, 
whilst>"the lower end of the same 
bone may be moved so as to lie to 
the inner side of the lower end 
of the ulna ; under these circum- 
stances it becomes necessary that 
the shaft of the radius should pass 
obliquely across and lie in front of 
the shaft of the ulna, and it is this 
difference in the relative position 
of the bones which chiefly explains 
the alterations in form and out- 
line wdiich we recognize when the 
limb is in the prone and supine 
positions respectively (see Fig. 97). 
In addition to the ligaments 
which bind together the bones of 
the fore -arm at the points above 
described, there is a strong fibrous 
sheet, called the interosseous mem- 
hrane^ which unites the shafts of 
the bones throughout almost their 

entire length. We are not much concerned with this layer, 
except to point out that it affords extensive attachments 




Fig. 97. Diagram to illus- 
trate the position of the 
bones of the right fore-arm 
and the position of the hand 
in pronation and sui)ination. 

The simple outlines represent 
the position of the bones and 
hand in supination. 

The dotted outline and shaded 
parts represent the position of 
the bones and hand in prona- 
tion. The radius now lies ob- 
liquely across the front of tbe 
ulna, and the thumb lies to the 
inner side with the buck of the 
hand directed forwards. 



1 86 



Wrist-joint 



to the deep muscles on both the front and back of the 
fore-arm. Its position varies according to the relation of 
the bones in pronation and supination, and it is necessarily 
associated with alterations in the forms of the muscles which 
are connected with it, alterations which react to a greater or 

less extent on the surface 
contours. 

As many of the muscles in 
the fore-arm are associated 
with the movements of the 
hand, it will be necessary 
next to consider the anatomy 
of the wrist-joint. 

The skeleton of the palm 
of the hand consists of five 
bones called metacarpal (Fig. 
98). These are described as 
long bones, each possessing 
a shaft and two extremities. 
By one end they articulate 
with and support the pha- 
la7iges, or hones of the fingers; 
Fia.f,8. The bones of the right wrist by the other they are united 

by a series of complex joints 
with a number of small bones, 
called the tcrist or carpal 
bones, which intervene be- 
tween them and the bones of 
the fore-arm. These carpal 
l>onos are ei/^4it in number, and exceedingly irregular in 
their form, but united together they constitute a compact 
mass (Fig. 99) which presents for examination certain very 
<:liara<!t('ristic features. 

It will Ik; wcill here to recall to mind certain points in 
regard to ih.', shucture of the lower ends of the ulna and 




and hand seen from the front. 

r. Ra<liaa. 

u Cliiu. 

a. Styl .id proross of radins. 

c Styloid process of uhm. 

'• c. The carpal bones (8), 

" m. The motacarj.ul hones '=;). 

f jt. Tho fingor-ljoiies or pluiianges (14), 



Bones of the Wrist 



187 




radius, to which reference has been akeady made. The 
lower end of the radius is much expanded, presenting on 
its inferior aspect a somewhat triangular- shaped articular 
surface, which is hollowed out from side to side and from 
before backwards. The apex of this triangle corresponds 
externally to the pointed projection called the sti/loid process, 
whilst its base is that edge which is directed towards the 
ulna. 

This styloid process can be dis- 
tinctly felt at the outer side of the 
wrist where it lies in line with 
the outstretched thumb. Its pro- 
minence is to some extent masked 
by the tendons which overlie it. 

The inferior end of the ulna is 
small, and does not reach so low 
in the limb as the radius ; for 
we have seen that the triangular 
fibro-cartilage, already described 
in connexion with the lower arti- 
culation between the radius and 
ulna, passes across its lower aspect, 
being attached internally to the 
base of the ulnar styloid process, 
and externally to the ridge which 
separates the carpal from the ulnar 
articular surface of the lower end 
of the radius (see Fig. 96). From this it appears that the 
lower end of the ulna does not directly articulate with the 
bones of the wrist, but only indirectly through the medium 
of the triangular fibro-cartilage. 

The ulnar styloid process projects from the inner and 
back part of the head of the bone, but, being overlain by 
tendons, is somewhat difficult to make out on the surface. 
It can best be felt in line with the inner border of tlie 



Fig. C.9. Tn this figure the 
carpal bones are shown se- 
parated from the radius and 
ulna of the right side. 

s. The tubercle of the scaphoid 
and 

t. The ridge on the trapezium 
forming the prominence at 
the root of the ball of the 
thumb. 

p. The pisiform and 

u. The hook-like process of the 
unciform forming the pro- 
minence at the root of the 
ball of the little finger. 



i88 Bones of the Wrist 

palm and to the inner side of the wrist when the hand 
is supine. Whilst this process has little influence on 
the surface forms, the part of the back of the head of the 
ulna immediately external to it forms the well-marked 
rounded elevation so characteristic of the wrist. This may 
best be seen when the hand is pronated, i. e. palm turned 
down, in which position the rounded eminence caused by it 
is seen on the back of the limb, just above the wrist-joint, 
and in line with the cleft between the little and ring 
fingers. The student will do well to contrast its appear- 
ance, in this position of the limb, with that in which the 
palm is directed upwards ; in the latter condition, whilst 
the head of the bone can be distinctly felt, its surface 
])rojection is now very much less apparent. 

The radius is the only bone of the fore-arm which enters 
directly into the formation of the wrist-joint, the head 
of 4:he ulna being, as already described, cut off from 
this articulation by the triangular fibro- cartilage already 
referred to ; but whilst this is the case both bones materially 
assist in supporting the joint, for they furnish attachments 
by their styloid processes for the lateral ligaments which 
strengthen the articulation. 

The eight bones ^ of the carpus, which form the complicated 
series of joints between the fore-arm and the skeleton of the 
palm, are arranged in two transverse rows of four each. 
Tho outer three bones of the first row provide a surface 
convex from side to side as well ^s from before back- 
wards, which articulates with the lower end of the radius 
externally, and tho under surface of the triangular fibro- 
cartilago internally. The bones of the second row arti- 
culate by means of an irregular joint with tho bones 

' TIk! bones of the first row, passing from the radial to the ulnar side 
of the wriht, are named [\w, scai)hoid, semilunar, cuneiform, pisiform ; 
IhojMj of th.' second row, the trapezium, trapezoid, os magnum, and 
unciform. 



Bones of the Wrist 



189 




of the first row, and themselves provide articular sur- 
faces for the bones of the palm. But these eight bones 
which constitute the two rows of the carpus are not united 
in such a way that the surfaces formed by their anterior and 
posterior aspects are flat. Their arrangement can best be 
understood by a diagram which represents a view of the 
carpal bones as seen on making a section across the wrist- 
joint (Fig. 100). From this it will be observed that the 
bones are grouped in such a manner as to form a deep groove 
anteriorly, whilst their posterior surfaces form a broad 
area, rounded from side to 
side. It is this surface which 
we can feel on the back of 
the wrist, where it is over- 
lain by the tendons of the 
various muscles passing down 
to the back of the hand. 

In regard to the anterior 
aspect of the wrist-bones 
they form, as has just been 
stated, a deep groove, the 
borders of which are out- 
standing and prominent. 
This groove is converted into 
a tunnel by a strong band, 

called the anterior annular ligament of the wrist, passing 
across it from one prominent border to the other. In this 
canal are lodged the tendons of the muscles, the fleshy 
bellies of which are placed in the fore-arm. It is these 
muscles which influence the movements of the thumb and 
fingers by bending them forwards. 

This arrangement is of advantage in retaining the flexor 
tendons in position when the wrist is bent forwards, other- 
wise they would be liable to be pulled out of place by the 
contraction of the muscles. 



Fig. ICO. A diagram to represent 
on a larger scale the appearance 
of the carpus when cut across at 
the dotted line shown in Fig. 98. 
The hollow in front of the carpus 
is converted into a canal by a 
ligament which stretches between 
the prominent inner and outer 
borders. 



190 



Bones of the Wrist 



If the student will but look at his own fore-arm, with the 
muscles strained and the wrist flexed, he will observe that 
all the tendons, which he can both feel and see, are firmly 
bound down as they cross the front of the joint. 

Returning now to the 
consideration of the promi- 
nent borders of this groove 
formed by the wrist-bones, 
the student will have no diffi- 
culty in recognizing the fol- 
lowing points. If the finger 
be placed on the ball of the 
thumb close to the wrist, and. 
in line with the cleft between 
the index ana middle fingers, 
he will recognize a bony 
prominence ; this is due to 
two of the bones of the wrist, 
called 5ca2?Ao2c? and trapezium^ 
which lie to the outer side of 
the groove. If the ball of 
the little finger be examined, 
a corresponding eminence 
will be noticed close to the 
level of the wrist and in line 
with the cleft between the 
little and ring fingers. This 
elevation is caused by the 
presence of a small rounded 




Fia. lor. Outline of the hand, 
showing the arrangement of the 
skin folds in front of the wrist 
and on the palms and fingers. The 
shaded ];arts indicate the positions 
of the bones which form the pro- 
minent inner and outer borJers of 
the carpus. Those at the ball of 
the thumb correspond from below 
upwards to the tubercle of the 
Kcaphoid and the ridge of the 
tt-apezium ; those on the ball of 
the little finder to the pisiform 
and hook-like process of the imci- 
form. 



pea-like bone, called the pisi- 
form bono. This ossicle does not enter into the formation 
of the joint between the radius and the first row of the 
wrist-bones, but articulates with the innermost bone of that 
row on its anterior surface. It thus helps to deepen the 
groove by causing a ])rojection along the inner border of 



Movements of the Wrist-joint 191 

the wrist; in front of this, but less distinctly felt, is the 
hook-like process of the unciform bone, the innermost of 
the bones of the second row of the carpus. It is to these 
prominences that the anterior annular ligament is attached, 
thereby converting the groove into a canal, as has been 
already described (see Figs. 99 and 100). 

The movements of the wrist-joint are necessarily com- 
plicated by the large number of articulations involved, but 
for present purposes it is not necessary to consider these 
movements in detail. 

The wrist may be bent forward, i. e. flexed, or bent back, 
i. e. extended. The former movement is freer than the 
latter. The wrist may also be moved from side to side, 
either to the inner or ulnar side, or to the outer or radial 
aspect. The former movement is frequently called adduction, 
the latter abduction. The range of movement towards 
the inner is greater than that towards the outer side. 
Further, these movements of flexion, extension, abduction, 
and adduction may be combined, constituting the movement 
of circumduction. The rotatory or twisting movement of 
the hand is effected, not at the wrist-joint, but by the 
crossing of the bones of the fore-arm, already alluded to 
under the terms pronation and supination (p. 178). 

In studying the muscles of the fore-arm we have to deal 
with an exceedingly complex mass, which not only controls 
the movements of pronation and supination and the move- 
ments of the wrist, but also those of the fingers. Of these 
nineteen muscles, four are concerned with the movements 
of pronation and supination, nine with the movements of 
the thumb and fingers, and six with those of the wrist. 
It is a point worthy of notice that a considerable number of 
the muscles lodged in the forearm, whilst indirectly con- 
trolling the movements of the wrist, are in their main 
action directly concerned with the movements of the fingers. 
It will be at once apparent that had accommodation for all 



ic)2 Bones of the Wrist 

these muscles, which act on the fingers, been provided in 
the hand itself, it would have involved a great increase in 
the size and bulk of that member, since the space required 
to lodge the fleshy fibres necessary to generate the force 
required would be considerable. To obviate this, nature 
has adopted the ingenious plan of placing the fleshy bellies 
of these muscles in the forearm and arranging for the 
transmission of the force to the moving parts by means of 
a series of long and slender tendons, which are easily 
accommodated, and take up but little room. In this way, 
the tapering form of the limb, which is small in the region 
of the wrist and of greater bulk higgler up, where the fleshy 
bellies of these muscles are situated, is easily accounted for. 

It is common knowledge that the flexor movements of 
the wrist and fingers are more powerful than the extensor 
actions. For this reason the flexor mass of muscles, viz. 
that disposed on the front of the limb, is larger and more 
strongly developed than that on the back of the forearm 
where lie the muscles associated with the extensor move- 
ments. In like manner it may be pointed out that the 
main flexor mass of the forearm arises from the internal 
condyle of the humerus, which is more prominent than the 
external condyle, from which springs the combined attach- 
ment of the extensors of the wrist and fingers, and it has 
been suggested that this disparity in the prominence of 
these condyles is directly associated with the functional 
activity of these two groups, since the flexors arising from 
the more prominent process act with greater mechanical 
ufl vantage than do the extensors, which are derived from 
the shorter external condyle. 

Happily for our purpose, a detailed description of many 
of those muscles is unnecessary, for a considerable number 
are so doc-ply placed that they do not directly influence the 
surface contours, though it should be clearly understood 
that indirectly thoy do modify the form of the limb, as in 



Pronators and Supinators 193 

a state of contraction they will cause a bulging forwards 
■ of the superficial muscles which overlie them. . 

• It is with the superficial muscles of the fore-arm that 
we are most concerned, since they are the direct deter- 
minants of the surface form. Before discussing these 
muscles in groups, however, a word or two may be said 
regarding the pronators and supinators^ i. e. the muscles 
which effect the movements of pronation and supination. 
These are all inserted into the radius, for, as we have 
already seen, it is that bone which moves in these acts. 
The pronators, of which there are two, must obviously take 
their origin from points internal to the radius, as they have 
to draw the radius inwards across the ulna, whilst the 
supinators, of which there are also two, must necessarily 
spring from points to the outer side of the radius in order 
to pull the radius back again to the outer side of the ulna. 
It follows from this that the two muscles of this group with 
which we are more immediately concerned, viz. ih.Q pronator 
radii teres and the supinator longus, will lie in relation to 
the inner and outer aspects of the fore-arm respectively. 
In this connexion the student will do well to remember 
the powerful action of the biceps muscle as a supinator, an 
action which has been already alluded to in the description 
of that muscle (p. 173). 

The superficial muscles of the fore-arm may be sub- 
divided into two groups, an outer and an inner, which lie 
along the corresponding sides of the fore- arm. Superiorly, 
the muscles of each group are attached to the condyles 
of the humerus, those of the outer group arising from 
the external condyle, those of the inner from the internal 
condyle. An inspection of the limb will enable the student 
to recognize that the fleshy bellies of the muscles are not 
confined to the sides of the fore-arm, but spread out on the 
front and back of the limb. Thus, the muscles which 
spring from the inner condyle of the humerus not only pass 

THOMSON O 



^9^ 



Muscles of the Fore-arm 



dowTi along the inner side of the fore-arm, but also clothe 
the anterior surface of the bones, whilst those which arise 




Fin. I02 Diac^rnm fo illiiPtrate 
thn arrangoment of tht; pronator 
and Bupi-rficial flexor muscles 
which arise from tho mtcmnl con- 
dyle and pans down the front and 
inner side of the forearm. 



1 JVonator rn'lii tfres. 

h KI<xor carpi radialia (rndinl flexor of 

tho wrigt). 
c. Kloxor Bublimin diRitorum (supcr- 

fi'-inl floxor of thfi finjTfirs). 
fi Kl.xor rnrpi ulnarig (ulnar floxor of 

tho wrigt). 




Fig. 103. Diagram to illustrate 
the arrangement of the superficial 
muscles (extensors and supina- 
tors) which arise from the external 
condyle and the ridge above it, and 
which pass down the back and 
outer side of the fore-arm. 

c. Supinator long;us. 

/. Extensor carpi radialis longior (long 
radial extensor of the wrist). 

g. Ex!ensor carpi radialis brovior (short 
radial extensor of tho wrist). 

li. Extensor communis digitorum (com- 
mon extensor of the fingers). 

i. Extensor carpi ulnaris (ulnar ex 
tensor of the wrist). 

j. Anconeus. 



from tlin oxtnrnal condyle pass down the outer side of the 
lirnb anrl spread backwards over its posterior aspect. The 



J 



Muscles of the Fore-arm 195 

• 

former group comprises the flexor muscles, wliich lie on 
the front ; the latter, the extensors, which lie on the back 
of the limb. As has been pointed out by Sir Charles Bell, 
owing to the fact that the internal condyle is the longer 
and more prominent of the two, the muscles arising from 
it, viz. those which bend the wrist forward and close the 
fingers, act with great mechanical advantage, much force 
being required to enable us firmly to grasp an object. 
On the other hand, the extensors of the wrist and fingers, 
arising as they do from the shorter external condyle, are 
weaker in their action : facts which are clearly demon- 
strated when we compare the force which can be exerted 
when we close the fist as contrasted with the power we 
can exercise in opening it. 

The greater bulk of the fore -arm above, and its tapering 
form below, are due to the fact that in the lower part of 
the limb the fleshy bellies of the muscles are replaced by 
their tendons, which obviously take up less room. 

Examining the muscles of the inner superficial group 
first, they will be found to take origin from the internal 
condyle of the humerus by a common tendon of attach- 
ment ; this group comprises the flexor muscles and one 
of the pronators, viz. the pronator radii teres. From this 
pointed superior attachment the fleshy mass spreads out 
below and is arranged in the following manner. The outer 
and most superficial part crosses the fore-a?rm obliquely 
from above downwards and outwards, and is inserted into 
the outer side of the shaft of the radius, about its middle ; 
this muscle is known by the name of the pronator radii 
teres (Pis., p. 72, 170 m, 382). 

Associated with the inner side of the origin of the pro- 
nator teres there is a well-marked fleshy belly, the muscular 
fibres of which are replaced by tendon about the middle 
of the fore-arm. This tendon may easily be recognized on 
the surface of the limb when the muscles are contracted ; 

o 2 



196 Flexors of the Wrist 

it will be found to pass down towards the radial or outer 
side of the wrist to the prominence which has been already 
described in connexion with the base of the ball of the 
thumb. Here it sinks deeply into the palm of the hand, 
into the second metacarpal bone of which it is inserted. 
The muscle is a flexor of the wrist-joint, and as its tendon 
passes to the radial or outer side of that articulation it is 
called the flexor carpi radialis (Pis., pp. 72, 162, 170 i?, 176, 

212, 382). 

If we return again to the internal condyle of the humerus, 
and trace the arrangement of the most internal fibres 
which spring from that process of bone, we find that they 
form a fleshy mass which lies along the inner side of 
the shaft of the ulna, connected therewith by a strong 
aponeurosis attached to the posterior or subcutaneous 
margin of that bone. From this extensive origin the 
fibres pass downwards and forwards, to end in the tendon of 
insertion which lies along the anterior border of the fleshy 
belly in its lower half This tendon may be traced along the 
front and inner side of the fore-arm to its insertion into 
the pisiform bone, which forms, as has been already stated, 
the prominence on the front and inner side of the wrist 
in lino with the cleft between the little and ring fingers. 
This muscle, like the last, is also a flexor of the wrist or 
carpus, but as it lies to the inner or ulnar side of the joint it 
'\^ C2t\\v(\ i\iQ flexor carpi uhiaris. Its tendon is not nearly 
80 prominent on the surface as that of the flexor carpi 
radialis, but its fleshy belly is of great importance in deter- 
mining the surface form, as to its presence is due the flowing 
outline of the inner side of the fore-arm from the internal 
condylo above to the wrist below (Pis., pp. 38, 44,50, 52, 94, 
98, 104, 158, 162, 170//, 176, 182, 200 Z, 212). 

Between the origins of the flexor carpi radialis and 
ulnaris from the internal condyle of the humerus there 
is froquontly a muscle which has a slender belly and a 



Muscles of Front of Fore-arm 197 

long thin tendon. The fleshy part of this muscle, which 
is called the palmaris longus, is wedged in between the 
bellies of the flexor carpi radialis and ulnaris, so that 
it is not readily distinguishable on the surface,, but helps 
to form the general rounded mass which springs from the 
internal condyle. Its slender tendon, which passes down 
the centre of the fore-arm to cross the middle of the wrist 
below and become attached to the dense fascia of the palm 
of the hand, can usually be readily recognized, particularly 
if the wrist be powerfully flexed. As however this muscle 
is absent in about 10 per cent, of us, the student need 
not be surprised if he occasionally meets with cases in 
which he, can obtain no evidence of its existence (Pis., 
pp. 170 r, 212, and those mentioned in previous paragraph). 
The muscles above described comprise the superficial 
part of the fleshy mass which has a common origin from 
the internal condyle of the humerus, but, whilst this mass 
is superficial in the sense that it is merely covered by the 
skin and fascia of the limb, the student should recollect 
that incorporated with the fascia, which overlies its com- 
mon origin, there is the insertion of the band of fascia 
derived from the biceps tendon. This insertion of the 
biceps into the fascia of the inner and upper aspect 
of the fore-arm has been already mentioned in connexion 
with the description of that muscle, but its influence on 
the surface contours may now perhaps be better understood. 
If the biceps be powerfully contracted this band will be 
rendered' very tight, and will produce a shallow oblique 
furrow overlying the fleshy bellies of the muscles which 
have just been described (Pis., pp. 44, 62, 126, 152, 162, 176, 
182). Another detail in connexion with the arrangement 
of the muscles just mentioned is one which should not 
be overlooked. In different individuals the proportion 
between the lengths of the fleshy and tendinous parts of the 
muscles varies, and this gives rise to individual differences 



198 Superficial Flexor of Fingers ' 

in the form of the limb. In a person in whom the fleshy 
part of the muscle is proportionately long the thickness of 
the fore-arm will be carried to a lower level, and vice versa. 

Underlying these superficial muscles we have others 
which are placed in front of the bones of the fore-arm. These 
are the superficial and deep flexors of the fingers and the 
long flexor of the thumb, together with a muscle called 
the pronator quadratus, the fibres of which cross over from 
the lower end of the ulna to the lower end of the radius. 
A detailed description of these muscles is however unneces- 
sary, as they do not directly influence the surface forms, the 
only exceptions being the tendons of the su;perjicial flexor 
of the fingers^ which, when powerfully contracted, appear in 
the intervals between the tendons already enumerated in the 
region of the wrist. Indirectly, however, these deep muscles 
do exert an influence on the contours of the limb, for they 
help to impart to it its characteristic roundness, and pad up, 
as it were, the superficial muscles which overlie them. The 
student may best observe this for himself by opening and 
closing the fist rapidly, when the slight changes in form 
'luo to the contraction of these muscles will be readily seen, 
particularly in the lower part of the fore-arm, where the 
retraction of the fascia covering the muscles renders more 
distinct the tendons of the superficial muscles already 
alluded to (PL, p. 170 2). 

Turning now to the consideration of the muscles which 
spring from the external condyle, the student will do well 
to remember two facts in this connexion : firstly, that the 
external condyle of the humerus is not so prominent as the 
internal ; and, secondly, that the origins of the muscles which 
lie along the outer side of the fore- arm are not confined to 
it, but ext(;nd for some very considerable distance above it, 
arising ironi the external condyloid ridge and from the 
oxternal intermuscular septum attached thereto. A know- 
ledge ol" these facta will do much to enable the student to 



Supinator longus 199 

appreciate the differences between the outer and inner 
outlines of the limb. 

The muscles which arise from this attachment consist 
of the supinators (two in number) and some of the extensor 
muscles of the wrist and fingers. Of the supinators we are 
concerned with one only, the supinator longus. This forms 
the highest of the fleshy fibres of the outer muscular mass, 
and arises from the upper two thirds of the external 
condyloid ridge, passing up to within an inch of the level 
of the lowest point of insertion of the deltoid, from 
which, however, it is separated by the fibres of origin of 
the brachialis anticus, as may be seen in the plate, p. 200. 
The belly of the muscle curves forward from this attach- 
ment to lie in front of the shaft of the radius, thus con- 
cealing the insertion of the pronator radii teres, and partially 
overlapping the belly of the flexor carpi radialis. It rests 
upon some of the other muscles to be presently described, and 
ends about the middle of the fore arm in a strong tendon, 
which passes downwards with a slight outward inclination 
towards the lower end of the radius, to the outer side of the 
base of the styloid process of which it is attached. The 
muscle is superficial throughout, except at its lower part, 
where its tendon of insertion is obliquely crossed by certain 
tendons to be mentioned later. As the name of the 
muscle implies, it acts as a supinator, i. e. it draws back the 
radius when that bone has been carried across the front 
of the ulna in pronation ; but from its relatively high, 
attachment to the humerus it also acts as a flexor of the 
elbow, an action which is easily demonstrated when one 
lifts a heavy weight with the limb in a bent position. 
Its influence on the suiface form is at once apparent, and 
is well seen in Pis., pp. 38, 126, 176, 182, 212 ; see also Pis., 
pp. 58, 62, 86, 148, 152, 162, 200, 212, 382. 

Beneath the foregoing muscle, and partially overlain 
by it in front, there are two muscles, which lie along the 



200 




d e f g h i j k I 7n n 
PRONE 



a. Deltoid. 

h. TrUtps. long head. 

c. 7ri(epi, outer head. 

d. True/is tendon. 

e. Krachialis anttcus. 
J. Triitfs, inner head. 



g. Supinator /oitgus. 

h. Exte' nal intermuscular septum. 

i. Extensor carpi radial is longtcr. 

j. Olecranon process o/ iihia. 

k. Anconeus. 

I. flexor carpi ulnar.s. 




n l> r Ide/ghijkl in }i o p q 7i r 

MIDWAY BETWEEN THE PRONE AND SUPINE POSITIONS 



t». /-xtensor carpi radialis Innior. 
M. Common extensor of the fingers, 
o. l- xtensor carpi ulnar is. 
f. Vina, subcutaneous posterior border. 
h.xlentor ossis tnetacarpi pollicts. 
xten for primi internodti polltcis. 



< 



r. Head oy ulna. 

s. Posterior annular ligament of -wrist. 

t. Biceps cubiti. 

ti. Tendons of radial extensors. 

V. Extensor secundi mternodii pollicis. 




I i 

./ e 



"^ 


K^5< 


m 


e 


^S^SI^P^ 


;.' 1 


• J 
! 1 


k 


/ 


>// It p <i 



SUPINE 



Radial Extensors 201 

outer side of the shaft of the radius ; the tendons of these 
muscles, however, pass to their insertion into the bones 
of the hand over the back of the wrist towards the outer 
or radial side : they are therefore extensors of the wrist 
and, named extensores carpi radiales, are distinguished 
from one another by being called long and short. 

The extensor carpi radialis longior is the more superficial 
of the two : it takes origin above from the lower third 
of the external cond^^loid ridge, that is to say, the part of 
the ridge below the attachment of the supinator longus. Its 
fleshy belly is directed obliquely forwards and downwards, 
so as to lie across the outer side and front of the upper part 
of the shaft of the radius ; in this position the muscle is in 
part covered by the belly of the supinator longus, only its 
posterior border and part of its outer surface being super- 
ficial. At a level corresponding to the junction of the 
middle with the upper third of the fore-arm the belly joins 
its tendon, which passes down in very close relation with 
that of the short radial extensor (Pis., pp. 200 i, 212 ; also 
pp. 38, 50, 126, 148, 152, 162, 170 w, 182). 

The extensor carpi radialis hrevior arises from the ex- 
ternal condyle of the humerus in conjunction with the 
remaining members of the superficial extensor group. At 
its upper attachment the muscle is covered by the fleshy 
fibres of the extensor carpi radialis longior, but, as its 
fleshy fibres are directed downwards along the outer side 
of the shaft of the radius, they appear superficial, lying 
external and posterior to the belly of the preceding muscle. 
The fleshy belly of the short radial extensor reaches 
a lower level than that of the long radial extensor in 
the fore-arm. It joins its tendon about the level of the 
junction of the middle with the lower third of the fore- 
arm. As stated above, the tendons of these two muscles 
are very closely related to one another ; they pass down 
to reach a groove on the back of the radius, just behind 



202 



Ulnar Extensor 



the styloid process of that bone. Beyond this point they 
cross the back of the wrist and are inserted into the back 
of the bases of the metacarpal bones ^ (bones of the palm) of 
the index and middle fingers. These tendons are not readily 
recognizable from the surface, for in the lower third of 
the fore-arm they are covered by two muscles which pass 
to the thumb, and on the level of the back of the wrist 
another tendon,- also passing to the thumb, crosses them 
obliquely. The action of these muscles is sufficiently 
indicated by their names ; they extend the wrist on the 
radial side (Pis., pp. 200 m, 212; also pp. 38, 50, 126, 148, 
152, 182, 382). 

Adopting the same method of description as has been 
employed in regard to the arrangement of the muscles 
which spring from the internal condyle, we shall next 
consider the most internal member of the group arising 
from the outer side of the external condyle. This muscle 
runs down in close relationship with the back of the shaft 
of the ulna, to the posterior border of which it is connected 
l)y means of an aponeurosis : it becomes tendinous on a level 
with the upper limit of the lower quarter of the fore arm, 
and from this point the tendon is directed downwards 
across the back of the wrist to the inner or ulnar side. 
As it passes over the lower extremity, or head of the ulna, 
it lies in a groove which is placed just behind the styloid 
process of that bone ; thence it proceeds to be inserted into 
the, l)ack of the base of the metacarpal bone of the little 
fing<'r. This muscle is called the extensor carpi ulnaris, or 
Wat ulnar extensor of the wrist (Pis., pp. 200 0, 212 ; also 
I'l'- 50. 14^. 152, 158* 162, 182). 9 

III this connexion it may be as well to remind the 
Hiii.l.iit of certain facts which have been already referred 

111.' Hkelelon of the palm is niado up of five bones called metacarpal 
lionrH ; (li.'He articulate above with the bones of the carpus or wrist, below 
with the iirht row of t lie phalai <res or finger-bonea. 



Ulnar Furrow 203 

to. In the description of the ulna it was stated that the 
posterior border of that bone was superficial throughout 
its entire extent. Commencing above at the triangular 
subcutaneous area, which corresponds to the back of the ole- 
cranon process or tip of the elbow, this margin of the shaft 
may be traced along the whole of the back of the fore- 
arm to the wrist below, where it ends on the enlargement 
produced by the lower end of the bone. The line so 
traced is not straight, but takes the form of a sinuous 
curve. The two ulnar muscles lie, one on the inner and 
the other on the outer side of this border ; that to the 
inner side is the flexor carpi ulnaris, while that which is 
placed along the outer or radial aspect is the extensor carpi 
ulnaris, just described. The bulging of these fleshy muscles 
on either side of this ridge of bone reacts on the surface 
form so as to produce a furrow between them. This surface 
depression is called the ulnar furrow, and the bottom of it 
corresponds to the posterior border of the bone. When the 
finger is run along it, one feels the ulna with the muscles 
above mentioned on either side. The furrow is of course 
best seen when the muscles are powerfully contracted, and 
it may be well to warn the student not to confuse it with 
the furrow which lies behind the back of the external 
condyle of the humerus and the upper end of the radius ; 
and, further, the reader should be careful to note that the 
two ulnar muscles are not in close relation throughout their 
entire extent, but are separated above by the interposition 
of the fibres of the anconeus muscle in addition to the 
expanded upper extremity of the ulna. These points may 
be rendered clearer by a reference to the plate (p. 200, 
Figs. I, 2 p ; also pp. 50, 162). 

Returning once more to the consideration of the super- 
ficial muscles which spring from the external condyle, 
and noting the fact that we have already traced the 
attachment and arrangement of the extensor carpi radialis 



204 Common Extensor of the Fingers 

brevior and the extensor carpi ulnaris, we have now to 
account for the interval between these muscles as they pass 
down along the radial and ulnar sides of the limb. This 
interval is filled up by a fleshy belly of the extensor 
communis digitorum, i. e. the common extensor muscle of the 
fingers. There are really two muscles here, the common 
extensor muscle of the fingers and a special extensor muscle 
of the little finger, but for our purpose we may disregard 
the latter altogether and consider the two as one. The 
fleshy mass of this muscle is wedged in between the origins 
of the short radial extensor, on the outer side, and the 
ulnar extensor on the inner side, and passes down 
the middle of the back of the fore-arm, occupying the 
interval between the foregoing muscles, which are widely 
separated below. The common extensor of the fingers, 
however, does not completely fill up this interval, but is 
separated from the tendon of the short radial extensor 
by some of the deeper muscles, which here * crop up ' so 
as to become superficial between the short radial extensor 
on the outer side and the common extensor of the fingers 
on the inner side. In the lower third of the fore-arm 
the fleshy fibres of the common extensor are replaced by 
a broad tendon, and this subsequently breaks up into a 
number of slips which, after crossing the centre of the 
Ijack of the wrist, spread out on the back of the hand 
to pass to their respective fingers. Throughout its entire 
Ifiugth the inner border of the muscle, i. e. that portion 
of it which forms the special extensor of the little finger, 
is in contact with the outer margin of the ulnar extensor, 
and tliis, as will be subsequently noticed, is represented 
by an intermuscular furrow on the surface of the limb. 
Tlio common extensor of the fingers acts primarily on 
the fingers, straightening them after they have been bent; 
but it also acts secondarily as an extensor of the wrist, 
UHsiHling in jmlling back the liand at that articulation (Pis., 



Depression behind Elbow 205 

p. 200. Figs. 2 and 3 n ; also pp. 50, 126, 148, 152, 162, 182, 
212, 382). 

As the tendons of these muscles, together with the tendons 
of others which still remain to be discussed, pass across the 
region of the wrist they are bound down by a ligament, 
called the posterior annular ligament. This arrangement 
is comparable to that already described on the front of the 
wrist, and prevents the displacement of the tendons in 
powerful extension or bending back of the wrist (Fig. 104). 

Attention should next be directed to the arrangement 
of the foregoing muscles as they are grouped behind the 
external condyle of the humerus. An examination of the 
plate, p. 2CX), Figs, i, 2, 3, and Pis., pp. 50 and 162, will show 
that there is a V-shaped area overlying the back and outer 
side of the elbow. The apex of the f\ corresponds to the 
back of the external condyle ; its outer limb is formed by 
the hinder border of the long radial extensor, whilst its 
inner side corresponds to the outer border of the anconeus. 
The floor of this space is made, up of the tendinous origins 
of the ulnar extensor of the wrist and the common extensor 
of the fingers. It results from this arrangement that when 
the limb is extended the borders of the muscles just 
enumerated become more prominent, and produce by their 
elevation of the surface a well-marked intermuscular de- 
pression between them, the bottom of which corresponds 
to the origins of the ulnar extensor and the common ex- 
tensor of the fingers. In this position these latter muscles 
overlie the back of the head of the radius, and as they are 
tendinous, rather than fleshy, it follows that we can easily 
recognize the head of the radius beneath them when we 
place our fingers in the hollow, the more so if, at the same 
time, we pronate and supinate the fore-arm so as to cause 
rotation of the head of the radius. The sharpness of the 
surface furrow which corresponds to these structures will, 
of course, largely depend on the absence of fat in the 



2o6 



Extensors of Thumb 



subcutaneous tissue, and on 




Fig, 104. View of the tendons 
an'l muscles on the back of the 
right hand. 

a. Ton-^lon of secundi internodii pol- 

licis. 

b. Tendon of primi internodii pollicis. 

c. Tendon of extensor carpi radialis 

lonifior. 
d Tondon of extensor carpi radialis 

breyior. 
'€■ P.*it«rior annular ligament of 

wrint. 
/ Ti-ndons of extensor communis 

digitorum. 
g T«M)don of oxtcngor minimi digiti. 
h Tfiidon of nxfenHor carpi ulnaris. 
i. T«ndon of floxor carpi ulnaris. 
/ M mcIm of hall of littlo finger soon 

from behind. 
If. Abdurtor indirin or first dorsal 

int«roM<-oui musrlc. 
III. 9>fr>,txi\, third, and fourth dorsal 

iiitfTossoi nmif IcK. 
in. Kxt«n»or tmnii metacarpi pollicis. 
u Adductor pollicis seen from be- 

bind. This muncle determines 

tho outline of the weh botwcon 

the thumb and the index finger 



the development and state of 
contraction of the muscles. 
As has been previously stated, 
in the female and child there 
is a larger amount of sub- 
cutaneous fat, and the sur- 
face form no longer displays 
the characteristic appearance 
above described, but exhibits 
only a shallow depression or 
dimple (Pis., pp. 52, 262, 308). 

As in the case of the front 
of the fore- arm, so on the 
back, we have to take into 
consideration the influence 
of the deeper muscles. Of 
these the most important are 
the extensor muscles of the 
thumb ; the others are not 
directly concerned in the 
moulding of the surface forms. 

The thumb, as we shall see 
hereafter, is the most impor- 
tant of all the digits : a fact 
which is further emphasized 
by the number of muscles 
connected with it. Of these, 
three must be studied in con- 
nexion with the back of the 
fore-arm. If the thumb be 
forcibly drawn away from 
the palm, one has no difficulty 
in recognizing two cord-like 
tendons running from the 
outer side and back of the 



Extensors of Thumb 207 

wrist to the first joint, or knuckle, of the thumb ; these are 
the tendons of the special extensors of this digit. The fleshy 
bellies of the muscles with which they are connected arise 
from the back of the bones of the fore-arm beneath the 
common extensor of the fingers and the ulnar extensor of 
the wrist. The two highest, called respectively the extensor 
ossis metacarpi pollicis (extensor of the metacarpal bone of 
the thumb) and extensor primi internodii pollicis (extensor 
of the first finger-bone or phalanx of the thumb), appear 
about the lower third of the fore-arm as two little fleshy 
bellies in the interval between the common extensor of the 
fingers and the short radial extensor. Having become super- 
ficial in this position, the two muscular slips end in tendons 
which curve downwards and outwards over the lower end 
of the radius to reach the outer side of its styloid process in 
a groove on which they are lodged. Below this point the 
tendons, which are indistinguishable, can be traced to the 
thumb, one becoming attached to the metacarpal bone of 
that digit, whilst the other passes along the back of that bone 
over the first knuckle to be inserted into the first phalanx 
of the thumb. The fleshy parts of these small muscles lie 
obliquely across the tendons of the long and short radial 
extensors as they pass down on the back of the lower end 
of the radius, and the tendons of these extensors of the 
thumb also overlie the tendinous insertion of the supinator 
longus. The student will do well to realize the importance 
of these small muscles as determinants of surface form. It 
is to their presence .that the outline of the lower part of the 
external border of the fore-arm is to some extent due. Much 
will depend on their development, but the reader can easily 
satisfy himself as to their position by rapidly moving the 
thumb from and to the palm. Their tendons form a promi- 
nent ridge leading up the back and outer side of the thumb, 
whilst their fleshy bellies cause a distinct elevation having 
an oblique direction across the lower end of the radius from 



2o8 Summary of Muscles of Fore-arm 

behind forwards (Pis, pp. 170, Fig. i w, 200 q ; also pp. 38, 72, 
86, 126, 162, 176, 182, 212, 216, 382). 

The remaining extensor of the xhumh— extensor secundi 
internodii poinds (extensor of the second finger-bone of the 
thumb)— may be briefly dismissed. The fleshy part scarcely 
becomes supei-ficial, and it is therefore onjy the tendon of 
this muscle which is noteworthy. If the thumb be forcibly 
drawn away from the palm, a prominent ridge caused by 
this tendon will be observed crossing the back of the wrist 
and hand obliquely from a point above in line with the 
clefl between the index and middle fingers, towards the 
first knuckle of the thumb below, over which, it may be 
traced onward to reach the second or terminal phalanx of 
that digit. As the tendons of this muscle and those just 
described pass over the back and outer side of the lower 
end of the radius they are separated by an interval of 
about an inch. If the thumb be forcibly drawn away from 
the palm, they are rendered tense and stretch the skin 
over them so as to produce a little hollow, corresponding 
to the interval between them. This hollow has been called 
by the French ' la tabatiere anatomique ', from the circum- 
stance that it was frequently used to measure a convenient 
doso of snufF (Pis, pp. 170, Fig. i v, 176, 182, 382). 

Having described the arrangement of the muscles of the 
foro-arm so far as is necessary for our purpose, the student 
is now ill a position to summarize many of the results 
obtained. Taking first the flexors and extensors of the 
wrist, these muscles are seen to be arranged in the following 
way. There is a group of ulnar flexors and extensors, and 
a group of radial flexors and extensors. The former lie 
along the ulnar or inner side of the fore-arm, the latter 
along the radial or outer side of the limb, but, whereas each 
group is further subdivided into a flexor and an extensor 
mass, it is sofm tliat along the inner side of the limb there 
is a flexor carpi ulnaris running down the front of the 



i 



Surface Contours of Fore-arm 209 

ulna and an extensor carpi ulnaris passing along the back 
of the same bone. In like manner the outer side of the 
limb is provided with a flexor carpi radialis muscle, which 
lies more or less in front of the radius, and an extensor 
muscle, made up of the extensores carpi radiales (longior 
and brevior), which runs down along the posterioi: and outer 
side of the same bone. Of the pronators and supinators we 
are concerned only with two, viz. the pronator radii teres^ 
which crosses the front of the limb obliquely from the 
internal condyle towards the middle of the shaft of the 
radius, and the supinator longus, which overlies the fleshy 
bellies of the long and short radial extensors as they pass 
down the outer side of the limb. The position of the 
remaining muscles has been sufficiently described ; they 
occupy the intervals between the radial and ulnar flexors 
in front, and the radial and ulnar extensors behind, and 
are flexor's or extensors in their action according as they 
lie on the front or back of the fore-arm. 

Hitherto the muscles of the fore-arm have been studied 
with the limb in the supine position, i. e. with the radius 
lying parallel to and along the outer side of the ulna. 
Under these conditions the outline of the limb, as viewed 
from front or back, corresponds on the inner side with the 
flowing curve produced by the fleshy belly of the flexor 
carpi ulnaris. On the outer side the outline is made up 
of three curves, the prominence of which varies accord- 
ing to the development of the muscles on which they 
depend. The highest of these curves commences above 
in the lower third of the upper arm, and sweeps over the 
region of the external condyle or outer elbow, to end below 
at the junction of the upper with the middle third of the 
fore-arm. This curve depends on the origin and attach- 
ment of the long supinator and the long radial extensor 
of the wrist. The second curve, opposite the middle third 
of the fore-arm, corresponds to the fleshy belly of the short 



THOMSON 



2IO 



Hollow in Front of Elbow 



radial extensor of the wrist. The third curve, generally 
less pronounced than the others, occupies the lower third 
of the limb ; it is due to the lower portion of the shaft of 
the radius and the tendons and muscles which overlie it, 
particularly the two extensor muscles of the thumb, viz. 
the extensor of the metacarpal bone and the extensor of 
the first phalanx (PL, p. 200, Figs, i and 2). 

When the limb is in the supine position the front of the 
fore-arm is somewhat flattened, and this flattened surface 
is continuous above with what is called the hollow in front 
of the elbow. This hollow is due to the V-shaped interval 
separating the muscles which spring respectively from the 
outer and inner sides of the lower end of the humerus. 
Thus, on the outer side, we find the interval bounded by 
the inner border of the long supinator, whilst internally 
the outer or upper border of the pronator radii teres forms 
its boundary. In the interval so formed, the biceps 
passes downwards to be inserted by means of its tendon 
into the tubercle of the radius. This causes a projection 
in the middle of the V'^li^ped intermuscular interval 
just described, so that the surface hollow presents rather 
the appearance of a Y-shaped furrow on either side of the 
lower part of the biceps muscle as it lies in front of 
the elbow. The two upper limbs of the Y ^^^ continuous 
above with the surface furrows which lie along the inner 
and outer sides of the belly of the biceps in the upper 
arm. As already stated, the inner of the two upper furrows 
is not 80 clearly seen as the outer, the reason being that 
the aponourotic insertion of the biceps into the fascia 
covering the muscles which spring from the internal 
condyle bridges over the interval, thus interrupting the 
groove and modifying considerably the surface form (see 
ante, p. 173; Pis., pp. 162, 170, Fig. i, 72, 382). The lower 
limb or stalk of the Y corresponds to the interval which 
separates the long supinator from the radial flexor of the 



Injluence of Position on Foi'm of Fore-arm 211 

wrist. This furrow is not noticeable to any extent wlien tlie 
fore-arm is in the supine position, but when the fore-arm is 
pronated it becomes quite distinct (PL, p. 170, Fig. i). 

The front of the elbow is crossed by a number of fine 
cutaneous creases ; these are due to the folding of the 
skin when the elbow is flexed. The most marked runs 
transversely across the hollow of the front of the elbow 
from one condyle of the humerus to the other. 

In a woman's arm the furrows above described are 
much less marked, as the subcutaneous fat imparts a more 
rounded form to the limb and masks the outline of the 
different muscles which, in the male, exercise so important an 
influence on the surface contours (Pis., pp. 72, 86, 434, 438). 

The influence of the change of position of the radius on 
the form of the limb when the fore-arm is pronated has 
been already dwelt upon in describing the movements of 
pronation and supination (p. 185). The student would do 
well to remember this fact, for not only does the radius 
move, but it carries with it the muscles which are grouped 
around it. Thus when, in the prone position, the shaft of 
the radius is thrown obliquely across the front of the ulna, 
so that its lower extremity comes to be placed internal 
to the head of the ulna at the wrist, the various muscles 
which lie along the outer and posterior surface of that 
bone are carried with it ; the supinator and extensor mass 
of muscles no longer lies along the outer and posterior 
aspect of the limb, but takes an oblique direction, from the 
external condyle of the humerus and the ridge leading 
to it, downwards and inwards towards the inner side of 
the wrist, where, as has just been said, the lower end of the 
radius is situated Over the lower end of this bone we 
have already seen that the tendons of the afore-mentioned 
muscles are carried in grooves in which they are retained 
by the posterior annular ligament of the wrist. By this 
arrangement the tendons are held in position, and when 

p 2 



212 





i 



Contours around Elbow 213 

the bone (radius) moves it necessarily carries with it the 
tendons which are lodged in the grooves on its surface. 

The modification in the form of the limb is thus explained. 
From being flattened from before backwards, and wide 
from side to side, as happens in the supine position, the 
fore- arm becomes rounded in the prone position, so that 
its thickness from before backwards exceeds slightly its 
width from side to side. It may here be pointed out that 
we usually carry our fore-arms in a position midway 
between extreme pronation and supination ; in other words, 
in walking we carry the limb with the palm of the hand 
directed towards the thigh, and not with the palms turned 
forwards, as in extreme supination, or backwards, as in 
extreme pronation (Pis., pp. 52, 54, 72, 86, 148, 382, 434, 

438). •' 

The modification in the arrangement and grouping of 
the muscles of the limb can best be studied by an examina- 
tion of the plates, pp. 170, 200, in which they are repre- 
sented with the limb in different positions. 

When the elbow-joint was described, the relation of its 
bony parts to the surface form was then discussed. Some- 
thing yet remains to be said regarding the changes 
in form due to the muscles of the fore-arm which are 
grouped around it. In the extended position of the joint, 
i. e. when the whole limb is straight, the outer condyle 
of the humerus is concealed by the muscles which overlie 
it, and spring from it, viz. the long supinator and extensors. 
In this connexion it is important to remember that two 
of these muscles, viz. the long supinator and the long radial 
extensor of the wrist, do not take origin from the external 
condyle, but from the external condyloid ridge above 
it. On the other hand, if we examine the inner side 
of the elbow there is no difficulty in recognizing the 
surface prominence which corresponds to the internal 
condyle of the humerus, for the pronator and flexor muscles, 



214 



Form of Bent Elbow 



which spring from this, do not extend upwards to any 
extent to be connected with the ridge above it (the internal 
condyloid ridge), but are confined in their attachment to the 
condyle itself, a circumstance which explains the character- 
istic prominence on the surface of this process of bone. As 
a result of these arrangements we can readily explain the 
marked differences which the limb presents when the elbow 
is bent, according as we view it from the outer or inner 




Fio. 105. Diaj^ram to .show the outline of the outer side of the arm 
wh-n the ..-Ihow is bent. The outline of the fore- arm at the elbow is 
• li-tcrmincd by the su))inator longas and extensor carpi radialis longior, 
which arise above the external condyle of the humerus. 

aspect (Pis., pp. 38, 44, 62, 126, 152, 158, 176, 182, 212, 
270). 

The angle formed by the outline of the fore-arm and 
the upper arm is placed much higher on the outer side 
of the elbow than on the inner; this is due to the fact that 
the long supinator takes origin from the external condyloid 
ndg(3 of the humerus, as high as the junction of the lower 
with the middle third of the length of that bone. This may 
l)« scM-n best when a heavy weight is raised with the elbow 
U'at; the lung supinator is tlu^n powerfully contracted, 



Form of Bent Elbow 



215 



and its anterior margin is rendered very tense, a condition 
shown in the diagram (Fig. 105). Not only is the belly 
of the supinator longus above the level of the joint, but 
the long radial extensor of the wrist is also seen powerfully 
contracted as it arises from the ridge on the humerus above 
the external condyle, the surface point corresponding to 
which is placed much below the level of the angle formed 
by the outline of the limb. When viewed from the inner 
side, the limb displays a marked contrast to the form just 




Fig. 106. Outline of the inner side of the arm T^'ith the elbow bent. 
The front of the fore-arm is in contact with the front of the upper arm, 
and forms a deep fold, at the bottom of which the internal condyle is 
situated. 



described ; a deep fold crosses the front and inner side 
of the elbow. This fold is produced by the approximation 
of the soft parts of the upper part of the limb with the 
anterior surface of the fore-arm, and its inner extremity 
passes in towards the surface prominence corresponding 
to the position of the internal condyle of the humerus. 
The depth of this fold will of course depend on the degree 
of flexion of the joint, being most marked when the joint 
is forcibly bent (Pis., pp. 38, 62, 104, 152). 

In lesser degrees of flexion, say about a right angle, the 



1 Rectus abdominis. 

2 External oblique. 

W Anteriorsii f^crior iliac s fine. 

4 Glutens medius. 

5 Ap<mniro5is of external 

oblique. 



It Vastus in t emus. 

15 Band of Richer. 

It) Vastus extern us. 

1 7 Rectus fcmoris ter.don. 

1 S Vastus internus. 

1 I Patella. 



28 T'ihia, s7ibcutaneous surface. 

29 Tibialis anticus. 

30 Soleus. 

31 Peroneus longus. 

32 Long- extensor of toes.. 
Z'-\ Peroneus brevis. 




ft ty>ut^ri^xlif;amfnt. 
7 'I fiiior Jntciae /ftnurit 
I* /lio ptoat. J'ectincn.<f. 
w SarloritiM, 

III I y / . < 

lit; Its. 

> IM. 

I" y attua txltrnuM. 



21 /.;,/. 

22 I'alcllar litfanienl. 
2:\ lli-adof Hl)ula. 

2 ( y endon of .V / r tortus. 

yr) t endon of .Setni-tcnditiosus. 

211 .SWrw.v. 

2<' Ciislrocncmius^ inner luad. 



34 I^ong flexor o/ toes. 

35 Long extensor of great toe. 
3() Internal malleolus ( tibia). 

37 Annular ligament of ankle. 

38 External malleolus. 

3.) I'.x/ensor bre-ris dic^itoriim. 
4(( Long extensor of great toe 
tendon. 



Superficial Veins of Arm , 217 

Y -shaped hollow of the front of the elbow becomes more 
pronounced, particularly if a powerful strain be put on 
the muscles, as in lifting a weight ; the outer side of the 
hollow is rendered more prominent by the tension of its 
outer boundary, the long supinator. The insertions of the 
biceps muscle, both tendinous and aponeurotic, are now 
well seen as they pass into the space. Such a view of the 
limb is shown in the plate, p. 176, Fig. i. 

In considering these details the student will do well 
to contrast the influence of powerful muscular contraction 
on the surface forms as compared with their appearance 
in moderate action, a difference which he can easily 
demonstrate on his own person. "We have here adopted 
the former condition as the one which enables us best 
to emphasize the influence of muscle in action on the 
contours of the limb, and it appears hardly necessary to 
dwell upon the fact that any pictorial representation of the 
parts in the condition above described would imply 
a vigorous use of the limb. Under ordinary circumstances, 
in moderate action the surface contours above mentioned 
would be much less definite. 

Mention may here be made of the arrangement of the 
superficial veins of the fore and upper arm and their 
influence on the surface form. The distribution of these 
veins is liable to great individual variation, but the usual 
arrangement is one in which we have veins running up 
the outer and inner sides, as well as along the centre 
of the fore-arm ; in front of the bend of the elbow they 
rearrange themselves so that there are only two superficial 
veins of any size in the upper arm ; these lie along the 
inner and outer sides of the biceps and occupy the corre- 
sponding furrows. These vessels become much engorged 
when the limb has been subjected to any violent muscular 
strain or prolonged effort, and the distended veins are 
readily recognized by the knotted cord-like ridges which 



2i8 Superficial Veins of Arm 

they produce on the surface of the limb (Pis., pp. 44, 72, 182, 
366). Their presence is also indicated by the bluish colour 
which they impart to the skin over them. In the antique 
the surface elevations produced by veins are frequently 
represented, and help to emphasize the ar list's representa- 
tion of the limb in violent action. A curious and not 
uninteresting detail may here be mentioned. This engorge- 
ment of the veins is always most marked when the limb is 
in such a position that the shoulder forms its highest point. 
If on the other hand, the arm be uplifted, the distension 
rapidly disappears and the veins are no longer recognizable 
by their influence on the surface contours. This statement, 
however, requires some, modification, for, if the course of a 
large vein be carefully examined when the blood has been 
suddenly drained from it, its position is in some cases, more 
particularly in those with thin skins and but little sub- 
cutaneous fat, indicated by a shallow furrowing of the surface, 
so slight, however, as almost to escape notice, and hence 
hardly worthy of representation in plastic art. This difference 
in the distension of the veins in these two positions of the 
limb is due to the fact that, in the first, the blood which is 
circulating in the veins is passing u^ towards the shoulder 
and has thus to counteract the influence of gravity, where- 
as when the arm is raised above the shoulder the blood 
flowing in that direction is assisted by the influence of 
gravity and is therefore more rapidly drained away. 
Consequently, if the artist wishes to be strictly accurate 
in his representation of the forms of the limb in action, 
ho sliould not emphasize the presence of these super- 
ficial veins on the surface of the uplifted arm, unless 
ot course he merely wishes to represent a momentary 
raising of the limb. On the other hand, their presence 
may bo clearly defined if the limb be represented on 
a low(!r level than the shoulder. 

rho pn)iniii('nc(3 of these superficial veins not only 



Front of Wrist 



219 



depends on their distension, but also on the thickness of 
the subcutaneous fatty layer in which they are imbedded. 
They are best marked as surface elevations when that 
layer is thin, as in a lean muscular model ; but their 
influence on the surface forms is masked when the fatty 
subcutaneous layer is thick, 
consequently it would be 
altogether contrary to artistic 
ideas to indicate them by 
surface elevations in any 
representation of a full and 
healthy female type. Under 
these circumstances their 
presence is sufficiently sug- 
gested by colour, and this 
especially as the finer and 
whiter skin of the female 
enhances the contrast. Par- 
ticularly is this the case in 
certain regions, viz. the front 
of the elbow and the front 
of the wrist, where the skin 
is thinner than elsewhere ; 
here a suggestion of this 
delicacy may be conveyed by 
representing the colourwhich 
the smaller veins impart to 
the surface. 

The surface relations of the 




Fig. 107. Outline of the hand, 
showing the arrangement of the 
skin folds in front of the wrist 
and on the palm and fingers. The 
shaded parts indicate the positions 
of the bones which form the pro- 
minent inner and outer borders of 
the carpus. Those at the ball of 
the thumb correspond from below 
upwards to the tubercle of the 
scaphoid and the ridge of the 
trapezium / those on the ball of 
the little finger to the pisiform 
and hook-like process of the unci- 
form. 



various structures met with 

in the region of the wrist have been already described ; 
but, in addition, the existence of certain lines or creases 
in the skin in front of this region must be noted. Of 
these there are two which are usually well defined. The 
lowest is a line with a double curve which sweeps across 



220 



Action of Mviscles 



the wrist, and corresponds to the bases of the elevations 
familiar to the reader as the ball of the thumb and the 
ball of the little finger. At some little distance above this, 
on a level with the tip of the styloid process of the radius, 
is a second delicate fold ; this becomes at once apparent 
as a line of flexure when we bend the wrist forwards. 
Other slight folds are rendered evident, lying more or less 
parallel to and above this, by further bending the hand 
forwards. 

The action of the various muscles described in the fore- 
arm is sufficiently indicated by their names. Those which 
flex and extend the wrist are assisted in their action 
by the muscles which bend and straighten the fingers. 

Abduction, or the action of drawing the hand towards the 
radial or outer side, is effected by the muscles which lie 
along the outer or radial side of the limb, viz. the radial 
flexor and the radial extensors of the wrist. 

Adduction, or the movement of the hand towards the 
ulnar or inner side of the limb, is caused by the combined 
action of the ulnar flexor and extensor of the wrist, which 
lie along the inner side of the fore-arm. 

The movement of circumduction of course necessitates 
a combination of the action of flexors, abductors, extensors, 
and adductors, or vice versa, according as the movement 
takes place from within outwards or from without inwards. 



CHAPTER VIII 

THE HAND 

The hand is one of the most characteristic features 
of man ; by means of it he is able to perform the most 
delicate manipulations. It may also be made use of as 
a means of expression. The actor's art is one of the 
most striking examples of this — the finger to the lips 
to indicate silence, the hands held up to express horror, 
are only instances of the more common modes of ex- 
pression by this means. This may be carried further, 
as in pantomime, and men who could not otherwise con- 
verse are enabled to interchange ideas by means of this 
gesture language. 

The artist will frequently have recourse to this mode of 
suggestion, as it enables him to assist in giving expression 
and action to the figures he represents. 

But in other ways the hand reflects to some extent the 
character and mode of life of its owner. Apart altogether 
from the refinement associated with the female, very great 
variations in the form of the hand are met with in different 
individuals, modifications in many instances due to the uses 
to which the hand has been put. To represent the hand 
of a blacksmith as delicate and refined would be absurd 
from a pictorial standpoint, though it is curious to note 
that the hands and fingers of those employed in the most 
delicate manipulations are often clumsy and uncouth look- 
ing. As a rule, however, we associate delicacy of hand with 
refinement and with mental rather than manual labour, 
whilst a muscular hand is regarded as an attribute of 
strength and of a powerful physique. A man's hands are 



222 



Skeleton of Hand 



often as characteristic as his face, and in portraiture the 
artist frequently avails himself of this feature. With 
women, however, this is less marked, as here we expect to 
see elegance and beauty rather than character, a circum- 
stance which has often led painters in the past to supply 

the hands from other and 
better models. 

The skeleton of the hand 
comprises the bones of the 
palm and fingers. The former 
consists of the five metacarpal 
bones already mentioned. 
These are long bones, long 
in the sense that they consist 
of a shaft and two extremi- 
ties; the upper end or base 
is directed towards the wrist, 
the lower end, which is 
rounded to form a head, sup- 
ports the bones of the digits. 
Of these five metacarpal bones, 
four are connected with the 
fingers, whilst one, the outer- 
most of the series, supports 
the thumb. The bases of 
these five bones articulate 
with the second row of the 
wrist or carpal bones. The 
heads or lower ends are 
arranged in the following way: — The four inner bones, viz. 
those which support the fingers, are united together by liga- 
inonts 80 that they cannot be separated from each other. 
Thr.y may bo regarded as almost immovable, for we possess 
littlo or no active control over their movements if we except 
tho innermost memb-r of the series, viz. that connected with 




Fio. 1 08. Tho bonos of the n>ht 
wrJHt and hand as seen from the 
front. 

r. Kadi us. 
". T'liin. 

n. Styloid procMg of radius. 
c. Styloid procoBs of ulna. 
C r. Tlio rrir|»al bones (8). 
w m. The niftacarpal bones (5). 
;• V Tho fintfor-bones or phalnnpna (14). 



Skeleton of Hand 223 

the little finger, the slight movements of which will be after- 
wards described. Whilst we cannot by the contraction of 
our muscles cause any alteration in the relative position 
of these bones to each other, they may, by the exercise of 
pressure, be moved to a slight extent. Thus by grasping 
the hand of another they may be crushed closer together, or 
by pressing the palm firmly against a flat surface they may 
be separated slightly from' each other. In marked contrast 
to this arrangement it must be observed that the lower end 
or head of the metacarpal bone of the thumb is free — that 
is to say, it is not connected with the heads of the other 
metacarpals by means of ligaments. It is this condition 
of the parts which enables us to draw the thumb away 
from the palm and fingers. The student will thus observe 
that it is only over the inner and outer members of this 
series of bones that we have any muscular control — the 
inner only to a slight degree, the outer or metacarpal of 
the thumb to a very great extent. 

The general form of the palm depends on its osseous 
framework, but it is only on the back of the hand that 
there is any distinct evidence of the arrangement and 
form of its bones, for on the front of the palm their out- 
line is concealed by the numerous muscles and tendons 
which overlie them. On the back of the hand there are 
no fleshy muscles to mask their outline, as here they 
are crossed merely by the tendons of the muscles going to 
the back of the flngers. The reader may satisfy himself as 
to this by feeling the back of his own hand, when the 
metacarpal bones of the flngers and thumb will be readily 
recognized in line with the several digits. If the flst be now 
closed the heads of these bones become at once apparent 
as a series of well-marked rounded elevations, familiar to 
all under the name of the first row of knuckles. According 
to the disposition of the fatty layer on the back of the hand, 
these knuckles will present a diflerent appearance when 



224 Skeleton of Hand 

the hand is ag-iiu opened and the fingers straightened. 
If the fat be absent or small in amount, the heads of the 
metacarpals, and the joints which they form with the first 
row of the bones of the fingers, will be seen to form a series 
of slight elevations covered with wrinkled skin, towards 
which the ridges formed by the several extensor tendons 
of the fingers may be traced ; but if, as in the ideal female 
hand, and also in that of the child, the fat is present in 
considerable quantity, the surface corresponding to the 
position of the knuckles is depressed and forms a series 
of hollows, or dimples, with but slight, if any, indication 
of the direction and position of the extensor tendons of 
the fingers. 

In regard to the joints between the bases of the meta- 
carpal bones, and the bones of the wrist, little need be said. 
The articulation so formed is curved from side to side, 
corresponding to the curve already described in connexion 
with the arrangement of the wrist-bones. This curve, it 
will be remembered, forms the sides and bottom of the 
tunnel, in front, through which the tendons of the flexors 
of the thumb and . fingers pass, whilst to its posterior 
convexity is due the side-to-side roundness on the back 
of the wrist. This arched arrangement is maintained 
throughout by the four inner metacarpal bones, a fact 
which can be easily demonstrated. If we lay the back 
of the hand on a flat surface, it will be found that it is 
impossible to bring all four inner knuckles of th^ first row 
into contact with the surface at the same time, unless we 
employ prf'ssure from above with the other hand. Further, 
tluH grouping of the metacarpal bones assists in forming 
the hollow of the palm, and imparts to the back of the hand 
itfl characteristic side-to-side convexity. It also explains ■ 
tho apparent separation of these bones, which has been fl 
alreudy a41udod to, when we bring great pressure to bear " 
on tho palm as it lies in contact with a flat surface, the 



Bones of the Fingers 225 

increase in width being due to a flattening out of this 
transverse arch. 

A notable exception to the foregoing arrangement is the 
metacarpal bone of the thumb. This articulates by means 
of a separate joint with the outermost bone (trapezium) of 
the second row of wrist-bones. The surfaces of this joint 
are of such a kind as to permit movement of every sort 
except rotation, and, owing to the fact that the lower end or 
head of the metacarpal bone is not united by ligaments 
to the other metacarpal bones, the thumb can be moved 
across or away from the palm, brought forwards or pulled 
backwards, or by the combination of these movements the 
act of circumduction may be performed. 

The first row of knuckles forms a series of rounded 
projections, which are due to the shape of the heads of the 
metacarpal bones. The bones of the first row oi phalanges^ 
or finger-bones, articulate with the rounded heads of the 
metacarpals by means of shallow hollow surfaces on their 
bases ; for, like the metacarpal bones, these phalanges are 
described as long bones, though in reality some of them 
are very short. Each digit possesses three such phalanges, 
with the exception of the thumb, which has only two. 
Each phalanx has a shaft and two extremities, upper and 
lower ; these extremities are articular, except in the case 
of the lower ends of the bones which are placed at the tips of 
the fingers, where each phalanx is furnished with a surface 
which affords attachment for the nail. 

The bones of the first row are the longest, those of the 
third row the shortest, whilst those of the second row are 
intermediate in length. Both the back and the front of 
these bones are overlain by the tendons of the fingers in 
such a way as to conceal their contours. When we bend the 
fingers the lower ends of the bones of the first and second 
rows of phalanges are seen to form the projections of the 
second and third rows of the knuckles. 

THOMSON Q 



226 Joints of Fingers 

If the reader will now compare the form of these 
knuckles with that of the first row, previously described, 
he will note a difference. Whereas the surface projection 
of the first row of knuckles was seen to be rounded, the 
outline of the second and third rows is flattened from 
side to side. This difference depends on the shape of the 
lower ends of the phalanges as compared with the heads of 
the metacarpal bones. As previously stated, the latter are 
rounded and fit into the shallow hollows on the upper 
ends of the first row of phalanges. The surfaces permit 
of movements in a backward and forward direction, i. e. 
bending or extending the fingers; in this respect the 
joints are hinge joints. At the same time, another move- 
ment is here possible : the phalanges may move from 
side to side on the rounded end of the metacarpal bone. 
This is demonstrated when we spread out the fingers or 
draw them together, a movement which we effect at the 
first knuckle-joint of the four fingers. This lateral play 
of the phalanx on the metacarpal bone is absent in the 
thumb, the corresponding joint of which permits only 
of flexion and extension. Such movement here is un- 
necessary, for we possess the power of pulling the meta- 
carpal bone of that digit away from or towards the palm, 
a movement which, in the other digits, is rendered im- 
possible by the fact that the heads of their metacarpal bones 
are bound together by ligaments. When we separate 
the fingers the movement is termed abduction ; when we 
bring them close together we adduct them. The line 
of the middle finger is regarded as the axis of the hand, 
from und towards which these movements take place. 
An examination of the articular surfaces of the other 
knuckles explains at once their difference in form as 
compared with those of the first row. The lower ends of 
the bones of the first and second rows of phalanges are 
provifh'd wilh two small rounded articular areas separated 



The Thumb 2.2.^ 

by a groove ; these fit into corresponding hollows on the 
upper ends of the bones with which they articulate, the 
two shallow hollows being separated by a slight ridge 
which fits into the groove above mentioned. Such a joint 
permits of movement only in one direction, viz. flexion 
and extension ; any lateral play is rendered impossible 
by the arrangement of its articular surfaces. This is 
the explanation why the surface form of the second and 
third rows of knuckles is squarer in outline than that of 
the first row, for the outline depends on the form of the 
lower ends of the phalanges of the first and second rows 
respectively ; indeed, a close inspection of these joints 
will show not only the squareness of the knuckle, but 
also a slight hollowing in the centre, which corresponds 
to the groove which separates the two small articular 
surfaces. This may best be seen in the second knuckle 
of the thumb. 

As will be gathered from the foregoing description, 
the thumb possesses a far freer range of movement than 
any of the other digits, and a moment's consideration will 
enable the reader to realize its great importance as a part 
of the hand. The thumb can be brought into opposition 
with each of the fingers ; in this way we can employ it 
and the finger with which it is brought into contact as 
a pair of forceps enabling us to pick up the most delicate 
objects. Perhaps the student will have this brought home 
more forcibly to him if he considers for a moment what 
the loss of the thumb entails. The fingers may, by the 
power of adduction which we possess, be brought together 
so as to clasp anything between them, but we have no 
longer the power of opposing them, as is the case with the 
thumb ; this fact can easily be demonstrated if the reader 
will endeavour to hold a pencil between any two fingers, and 
then try to make use of it. No doubt practice will assist 
us in acquiring a greater facility in holding anything in tliis 

Q 2 



228 Short Muscles of Thumb 

way, but it will be at once apparent that there is a vast 
difference between the use of the instrument so held, and 
the control which we can exercise over it when held by 
the thumb and finger. 

Accordingly, we find that the thumb is furnished with 
a large number of muscles, ^^ich not only move it in 
different directions, but which are sufficiently powerful 
to enable us to employ very considerable force. Some 
of these muscles have already been studied ; they are the 
long muscles of the thumb, and their fleshy bellies are placed 
in the fore-arm. But there is a group of short muscles, 
the fleshy parts of which lie in the hand itself. 

It is this latter group which forms the rounded elevation 
along the outer side of the palm and overlying the meta- 
carpal bone of the thumb, which is familiarly known as 
the hall of the thumb. 

This fleshy mass consists of the following muscles : a short 
flexor, an abductor, and an opponens of the thumb. We 
need not here enter into details regarding the precise 
attachment and position of these muscles ; their names 
have been mentioned in order that the reader may have 
somo idea of their action. Generally speaking, the afore- 
said muscles arise from tne wrist-bones which form the 
oxtornal ridge of the groove in which the flexor tendons 
of the fingers are lodged ; this ridge has been already 
referred to {ante, p. 190}, and was seen to consist of parts 
of the scaphoid and trapezium which form the elevation 
at tho base of the ball of the thumb on a line with the 
cleft between tho index and middle fingers. But as this 
ridgo affords attachment to the strong anterior annular 
ligament which bridges over the groove and converts it 
into a tunnel tho muscles of the above group also derive 
fibres of origin from this ligament. 

From this attachment tho fleshy fibres pass down to be 
attached to Iho bones of tho thumb. One is inserted into the 



Muscles of Thumb 



229 



shaft of the metacarpal bone, and forms the opponens polUcis, 
a muscle by which we are enabled to carry the thumb 
across the palm and so oppose it to the other fingers. The 




Fig. 109. Shows the arrangement 
of the structures in the palm. 

a. Palmar fascia, 

b. Tendon of the palmaris longus pass- 

ing into it. 
c c. The anterior annular ligament 
underneath which the tendons 
pass to the palm and lingers, 
d, e, and / are the muscles of the ball of 
the little finger. 

d. Opponens minimi digiti. 

e. Flexor brevis minimi digiti. 

f. Abductor minimi digiti. 

g, h, and i are the muscles of the ball of 
the thumb. 

g. Flexor brevis pollicis. 
h. Abductor pollicis. 

t. Opponens pollicis. 




Fig. no. A deeper view of some 
of the muscles of the hand. 

a. Abductor minimi digiti. 
6. Hook -like process of unciform (one of 
the bones of the carpus). 

c. Pisiform bone. 

d. Ulna. 

e. Radius. 

/. Opponens pollicis. 

g. Deep part of flexor brevis pollicis or 
oblique adductor. 

h. Superficial part of flexor brevis polli- 
cis and the abductor pollicis (cut). 

t. Adductor pollicis, or transverse ad- 
ductor, and 

j. Abductor indicis, or first dorsal inter- 
osseous muscle, both of which 
occupy the interval between the 
metacarpal bones of the thumb and 
index finger. 



remaining fibres, which consist of the flexor brevis pollicis 
and the abductor poll icis^ pass down to be inserted into the 
base of the first phalanx of the thumb in the following way. 



230 Muscles of Thumb 

The libres of the short flexor are connected with a little 
bone, called a sesamoid bone, which lies to the outer side 
of the front of the joint between the first phalanx of the 
thumb and its metacarpal bone. This little nodule of 
bone is provided with a cartilage-covered articular surface, 
which glides on the rounded surface of the outer part 
of the head of the metacarpal bone. From this sesamoid 
bone, which thus acts like a pulley, tendinous fibres pass 
to connect it with the outer side of the base of the first 
phalanx. Superficial to, and to the outer side of this 
sesamoid bone, though not connected with it, the abductor 
pollicis is found as it passes to its insertion into the outer 
side of the base of the first phalanx along with the fore- 
going. The abductor action of this muscle moves the 
thumb as a whole, and not the phalanx on the metacarpal 
bone, as is the case with the other fingers (Figs. 109, no). 

A small portion of the flexor brevis is inserted into 
a corresponding sesamoid bone on the inner side of the 
joint, by means of which it is connected with the inner 
side of the base of the first phalanx of the thumb. 

The thumb is also provided with adductor muscles, which, 
like the opponens, draw the thumb inwards towards the 
pahn : of these there are two, the oblique and the transverse 
adductors. The former has hitherto been described as the 
deep part of the short flexor, but the description here given 
is that now generally adopted. This muscle lies deeply 
in the palm, and, although covered by those already de- 
scribed, it assists in imparting to the ball of the thumb 
lU characteristic fullness. The oblique adductor is in 
l^roater part inserted into the inner sesamoid bone, but 
It also sends some fibres to the outer sesamoid as well, 
wlii(;h unite with those of the flexor brevis. Much more 
iini>orUnt from our standpoint is the transverse adductor. 
This muscle docis not assist in forming the swelling of the 
ball of the thumb, but lies internal to it; it helps to form 



Muscles of Thumb 231 

the fleshy mass which occupies the interval between the 
metacarpal bone of the thumb and that of the index finger. 
The muscle is fan-shaped ; by its pointed extremity it is 
united to the inner sesamoid bone along with the adductor 
obliquus, by its base it is attached to the front of the shaft 
of the metacarpal bone of the middle finger. AVhen the 
thumb is outstretched the lower border of the muscle 
can be distinctly felt about half an inch above the fold 
of skin which forms the web between the thumb and 
forefinger. By their connexion with the inner sesamoid 
bone both these muscles are attached to the base of the 
first phalanx on its inner side. As, however, the joint of 
the first knuckle of the thumb allows of no lateral play, 
but only of flexion and extension, these muscles do not 
move the phalanx, but act on the metacarpal bone with 
which the phalanx is connected. The presence of the 
small sesamoid bones imparts a fullness to the front of 
the joint which it would not otherwise possess (Fig. no). 

The adductor transversus, as above described, is not the 
only muscle which occupies the interval between the meta- 
carpal bones of the thumb and forefinger. If the reader 
will examine the back of his own hand with the thumb 
outstretched and the forefinger pulled as far apart from 
the middle finger as possible, he will observe a rounded 
elevation occupying the V-shaped interval between the 
metacarpal bones of the thumb and forefinger. This 
is due to the fleshy part of the abductor indicts. It is 
one of a series of muscles which lie between the meta- 
carpal bones of the digits, called the dorsal interossei^ and 
is hence sometimes called the, first dorsal interosseous mMsde. 
The former name is the better for present purposes, as it 
indicates the action of the muscle. It arises by fleshy fibres 
which are attached to the metacarpal bones of the thumb 
and index finger respectively, as they lie on either side of 
the V-shaped interval. These fibres unite to form a fleshy 



232 



Abductor indicis 




belly which is i)laced along the radial side of the metacarpal 

bone of the index finger, and 
terminate, near its lower ex- 
tremity, in a tendon which 
runs down the radial side oi 
the first knuckle of the fore- 
finger, to become attached to 
the base of the first phalanx 
of that digit along with the 
extensor tendons. This muscle 
lies behind the transverse 
adductor of the thumb, and 
when we grasp the fleshy 
layers between the thumb 
and fore-finger we compress 
these two muscles between 
our fingers. 

Just as the outer diQ,it or 
thumb is provided with short 
muscles, so the inner digit 
or little finger is similarly 
equipped, though the muscles 
of the latter are much smaller 
and less powerful than those 
of the former. This is at 
once apparent if we compare 
the prominence of the ball 
of the little finger with that 
of the thumb. 

The hall of the little finger 
consists of the following 
muscles, an abductor^ a short 
jlexor^ and an opponens. The 
two former are inserted into 
the inner side of the base 



Fig. III. View of the tendons 
and luupcles on the back of the 
right hand. 

a. Tendon of secundi intemodii pol- 

licig. 
I. Tendon of piiiui intemodii pollicis. 

c. Tondon of extensor carjii radialis 

longior. 

d. Tendon of extensor carpi radialis 

brcvior. 
««. Posterior aiinulur ligament of 

wriKt. 
/. Tendong of extensor communis 

diRitorum. 
g. Tendon of extensor minimi digiti. 
h Ti»ndon of extensor carpi ulnaris. 
i Tendon of flexor carjii ulnaris. 
/ Mns<;lr.« of hull of little flnger seen 

from behind. 
k Ah.Iuctor in<li(Ms or firHt dorsal 

Jnt«rr)itieous muscle. 
/. Second, thinl, and fourth dorsal 

intentsei inusdeg. 
m. Kxt*ns«ir osmIs niotacarpi iiolljcis. 
u. Addi.rtor p.dlicis soon from bo- 

ln««'l. This musdo determines 

th« outlin« of the web between 

the thuM.h and the index finger. 



Muscles of Little Finger 233 

r. 

of the first phalanx of the finger, whilst the opponens is 
attached to the inner side of the whole length of the shaft 
of its metacarpal bone. These muscles arise more or less 
in common from the ridge on the inner side of the wrist, 
formed mainly, as we have already seen, by the pisiform 
bone, together with a process of another bone called the 
unciform. The former causes the elevation, already 
referred to, which may be seen and felt at the root of the 
ball of the little finger, on a line with the cleft between 
the little and ring fingers, and towards which the tendon 
of the fiexor carpi ulnaris can be traced {ante, p. 190). In 
addition some fibres of this fleshy mass arise from the 
anterior annular ligament. The action of these muscles is 
sufficiently indicated by their name, though it may be well 
to note a difference in the action of the abductor of the 
little finger as compared with that of the thumb. This 
muscle draws the little finger away from the ring finger at 
the first knuckle-joint, a movement which is impossible in 
the thumb, as the corresponding joint of that digit allows 
of no lateral play. The. action of the opponens muscle 
of the little finger is much more limited than that of the 
thumb, because the head of the metacarpal bone of the little 
finger is bound to that of the ring finger by ligaments. 
The movement is therefore limited to a slight drawing 
forward of the metacarpal bone which helps to deepen the 
hollow of the palm (Figs. 109, no). 

Between the two muscular prominences above described, 
the palm is hollowed out from side to side and slightly also 
from above downwards. If the fingers be pressed into 
this hollow the skin is felt to be firm and resistant. This 
is due to the fact that there is a dense layer of fibrous 
tissue, called the palmar fascia, immediately beneath 
and intimately connected with the skin in this situation. 
This fascia is somewhat triangular in shape ; its narrow 
or pointed end is united to the anterior annular ligament 



OQ1 The Palm 

-34 ^ 

which bridges across the groove formed by the wrist- 
bones, whilst its broad end or base is directed towards 
the roots of the fingers, with the tendon sheaths of which 
it is connected. On either side this fascia thins out, 
furnishing fibrous expansions which cover the muscles of 
the balls of the thumb and little finger respectively ; the 
middle portion is, however, by far the strongest. All 
the flexor tendons of the fingers, together with a number 
of blood-vessels and delicate nerves, pass underneath this 
fascia, so that ample protection is afforded to these structures, 
a most important detail when we remember how frequently 
we grasp the handle of a tool and thus subject the deli- 
cate parts within the palm to the influence of direct 
pressure. 

The skin of the palm varies in thickness in different 
places ; it is thick in the centre and along the inner side 
where it covers the ball of the little finger, thinner where 
it passes over the muscles of the thumb. The thickness 
of the skin of course depends on the occupation of the 
individual, ' the horny-handed son of toil ' in this respect 
presenting a marked contrast to the appearance displayed 
by one who has never been required to engage in hard 
manual labour. The palm presents a series of small rounded 
elevations or pads just before the fingers spring from it. 
These prominences, of which there are three, lie rather 
in the intervals between than over the roots of the fingers. 
\ lowed from the front, the webs between the fingers, and 
the skin creases which cross the roots of the fingers, 
form a well-defined line with a flowing curve from with- 
out inwards which limits inferiorly the region of the 
palm. 

A number of well-marked creases or folds are seen 
croHsin^r the p.^i„^ jj^ different directions. Of these, four 
are u.suully well marked, two having a somewhat trans- 
verso direction, whilst tlicj other two pass more or less 



The Palm 



# 



235 



longitudinally ; their arrangement has been described as 
resembling the written capital M placed obliquely across the 
palm. The lower of these transverse lines may be traced 
from the inner border of the hand, about an inch above 
the level of the web between the little and ring fingers, 
across the palm curving 
downward towards the cleft 
between the middle and fore 
fingers. The second trans- 
verse line commences about 
an inch above the web of the 
index and middle fingers, and, 
curving upward, crosses the 
palm to be gradually lost on 
the surface of the ball of the 
little finger. If the student 
will examine these lines with 
the fingers straight and the 
palm stretched, and then pro- 
ceed to bend the fingers on 
the palm, he will at once 
recognize that they are lines 
of flexion and correspond to 
the infolding of the skin over 
the joints between the meta- 
carpal bones of the fingers and 
the first row of phalanges. 

In like manner the two 
longitudinal lines, one sweep- 




FiG. 112. Outline of the hand, 
showing the arrangement of the 
skin folds in front of the wrist 
and on the palm and fingers. The 
shaded parts indicate the positions 
of the bones which form the pro- 
minent inner and outer borders of 
the carpus. Those at the ball of 
the thumb correspond from below 
upwards to the tubercle of the 
scaphoid and the ridge of the 
trapezium ; those on the ball of 
the little finger to the pisiform 
and hook-like process of the unci- 
form. 



ing round the ball of the 
thumb, the other running down the centre of the palm, are 
at once seen to be associated with the movements by which 
the hollow of the palm is deepened by the approximation 
of its inner and outer borders through the action of the 
opposing muscles of the thumb and little finger. 



236 The Fingers 

To apply any other significance to these lines is at once 
an imposition and a fraud. 

Many persons possess the power of wrinkling the skin 
along the inner border of the palm overlying the ball 
of the little finger ; this is due to the action of a small 
superficial muscle, called the palmaris hrevis, the scattered 
fibres of which have a transverse direction across the upper 
and inner side of the palm, from the dense fascia of which 
they take origin, whilst by their inner ends they are 
attached to the skin. 

The four fingers as they spring from the palm are united 
by skin folds, which form the webs of the fingers. These 
folds unite the fingers at a level corresponding to the 
middle of the first row of phalanges or finger bones, so that 
a considerable portion of the palm is formed by the bases 
of these bones and their articulation with the metacarpals. 
The part of the palm which lies below the level of the two 
transverse folds aforementioned corresponds to the roots 
of the fingers. As we shall see, this is one of the reasons 
why the fingers appear shorter when viewed from the front 
than from the back. 

The fingers should taper regularly from base to tip, 
and should not display any thickening at the joints. The 
rounded form of the anterior surface is due to the tendons 
wliich pass down the front of the phalanges. These 
tendons are enclosed in a strong sheath, which, however, 
18 much thinner where it crosses the front of the joints. 
The surface roundness is somewhat constricted over each 
joint, where delicate skin folds are seen. These are lines 
ol llexion, and are arranged as follows : on a level with the 
web of the fingers, the index and little fingers are crossed 
hy a single line, the middle and ring fingers by two lines. 
In front of the second joint each finger is crossed by two 
folds, there being only one transverse crease in front of 
the third joints. The tips of the fingers are provided with 



Back of Hand . 237 

well-marked ' pulps ' covering the front and ends of the 
third row of finger-bones, which in their turn support 
the nails. 

The skin in front of the first joint of the thumb is 
crossed by an oblique fold which passes upwards and out- 
wards from the web between the thumb and forefinger. 
Two creases cross the front of the second joint. 

The appearance of the back of the hand varies much, 
according to the amount of fat distributed in the sub- 
cutaneous layers. The general surface is convex from side, 
to side, superiorly it is carried up into the roundness 
of the wrist. The manner in which the wrist is united 
to the hand varies in different individuals; in some the 
outline of the back of the arm is carried down as a more 
or less straight line on to the back of the hand. In 
the more refined and beautiful type, however, the flow 
of this line is interrupted by a rounded curve over the 
back of the wrist, which thus interrupts the continuity 
of the outline of the fore-arm and that of the back of 
the hand. This graceful contour is further emphasized if, 
at the same time, the fingers are slightly hyper-extended. 
These remarks apply particularly to the hands of women, 
in whom we expect to find suppleness and grace rather 
than firmness and strength. 

The skin over the back of the hand is thin and trans- 
parent, enabling us to recognize easily the position of the 
superficial veins either by their colour or prominence ; 
the latter would be justifiable in a representation of a male 
ha^nd, but would be entirely out of place if indicated in the 
female, unless it be the hand of an old woman in whom 
the wasting of the fat has led to an undue prominence 
of the vessels. In man these superficial veins are seen to 
form an irregular arch across the back of the hand from 
which the blood passes up by the superficial veins of the 
fore-arm already noticed {ante, p. 218). 



238 Back of Hand 

The appearance of the first row of knuckles lias been 
previously alluded to. In hands in which the tendons are 
easily seen these will be noticed, when in a state of tension, 
forming a series of ridges passing down from the middle 
of the back of the wrist to the first row of knuckles, 
over which they are carried on to the backs of the fingers. 
The tendons which form the most pronounced ridges on the 
surface are those associated with the thumb. These we 
have already described in connexion with the wrist-joint 
and the muscles of the fore-arm. They are the extensors 
of the metacarpal bone and phalanges of the thumb. That 
passing to the second phalanx forms the salient ridge which 
is plainly visible when we strongly extend the thumb; 
this ridge is seen to pass from a point on the back of 
the wrist in line with the cleft between the index and 
middle fingers, downwards towards the first knuckle of the 
thumb, after which it is carried along the back of the first 
j)halanx to reach the base of the second, to which the 
tendon is attached. 

The manner in which the fingers spring from the back 
of the hand is very different from what we have seen in 
front. If the fingers be spread out, the webs between 
them will bo noticed to be attached to the sides of the 
fingers much lower down in front, where they form a sharp 
abrupt fold which stretches across the interval between 
the fingers on a level with the middle of the first phalanges. 
Above and behind this the skin between the fingers forms 
a broad groove when the fingers are outspread, which 
gradually ikdes away on the back of the hand in the 
int^irvals between the knuckles of the first row. When 
the fingers are again brought together these furrows are 
represented by a series of folds which carry upwards the 
outlino of the fingers on to the back of the hand. It is for 
this reason that the fingers of the hand appear much longer 
when viewed frr.m the back than from the front, for on 



Back of Hand 239 

the back the whole length of the phalanges of the first row 
is seen to enter into the construction of the fingers, whereas 
on the palmar surface nearly half the length of these bones 
is concealed in the fore-part of the palm. The reader may 
at once satisfy himself as to the correctness of this explanation 
if he examines his two hands placed side by side, the one 
palm upwards, the other palm downwards (Fig. 113). 

The flow of the lines which separate the fingers behind, 
when closely approximated, is peculiar. The lines on either 
side of the middle finger take different directions, that 
between the middle and index fingers passing outwards 
towards the thumb, the other between the middle and ring 
fingers being directed towards the inner border of the hand, 
a direction which is also followed by the line between the 
ring and little fingers. The direction of these lines is 
determined by the position and direction of the tendons 
of certain small muscles lodged between the shafts of the 
metacarpal bones, and called the dorsal intero-ssei. The 
middle finger is provided with two of these muscles, one 
on either side, and it is the tendons of these muscles, 
as they pass down to be attached on either side to the first 
phalanx, which account for the flow of the lines in opposite 
directions. The corresponding muscle of the ring finger 
is attached to the ulnar side of the first phalanx of that 
digit (Fig. III). 

In the extended position of the fingers the skin is seen 
to be much wrinkled over the second row of knuckles, less 
so over the third, beyond which we find the nails. 

Well-shaped nails should be long and not too broad ; 
straight or but slightly curved in their long direction ; 
arched from side to side. The nail of the forefinger is the 
least curved from side to side, that of the little finger 
the most curved. Short, broad, and flat nails are an un- 
pleasant feature in the hand. 

The length of the fingers varies in different individuals, 



240 Back of Fingers 

but as a rule, in a well-formed hand, the relative lengths of 
the digits are approximately as follows. The middle finger 
is the longest ; the tip of the index finger corresponds 
pretty closely to the level of the root of the nail of the 
middle finger. The ring finger reaches as low as the level 
of the middle of the nail of the middle finger, and is thus 
slightly longer than the index finger ; the little finger 
reaches to the level of the third joint of the ring finger ; 
whilst the thumb, when closely applied to the outer side of 
the fore-finger, should reach the level of the second joint 
of that digit, though it is frequently somewhat shorter. 
It is not unfrequent however to meet with the index finger 
as long as the ring finger. Seen from the front, the middle 
finger appears shorter than the palm, viewed from the back 
it appears longer than the back of the hand. 

When the fingers are bent the length of their dorsal 
surface is increased ; this is at once apparent if we examine 
the condition of the skin. When the fingers are straight 
the skin over the knuckles is puckered and wrinkled ; 
when bent, the skin becomes tense and stretched over the 
joints, thus indicating that there has been an increase in 
the length of the finger on its dorsal aspect. This increase 
is duo to the fact that the thickness of the lower articular 
ends of the metacarpal bones and first two rows of pha- 
langes has now to be taken into account. The accompanying 
diagrams will at once make this clear (Figs. 113, 114). 

As a rule, extension of the fingers is limited to bringing 
them info a straight lino with the palm, but many persons 
possess the power of bending back the fingers to a slight 
degree at the first row of knuckles, and also at the 
other joints. This hyper-extension at the first joints of 
the fingers is most easily effected when the other joints 
are slightly bent, and the appearance produced conveys 
an impression of suppleness and grace particularly plea- 
sant in a wpll-niodcllod female hand. The movement 



Movements of Fingers 



241 



just described is an active movement, i. e. one controlled 
by the muscles of the individual, and must not be con- 
fused with passive hyper-extension which is caused by 
pressing back the fingers. The extent to which this may 
be carried will depend on the looseness of the joints and 
the amount of pressure employed. 

It may be pointed out, in connexion with the movements 
of the thumb, that flexion at the first knuckle is limited 
in range, whilst at the corresponding joints of the other 
fingers bending may take place to form a right angle ; in 
the thumb we can only flex it so as to include an angle 





Fig. 113. Fig. 114. 

Diagrams to show how the length of the dorsal surface of the finger 
is increased during flexion by the sum of the thickness of the meta- 
carpal and phalangeal bones of the first and second row. In Fig. 113 the 
dotted line represents the attachment of the web between the fingers, 
showing how the fingers seem longer when viewed from behind than 
in front. 

of about one hundred and twenty or one hundred and 
thirty degrees. 

In summing up the facts in regard to the hand, the student 
will now realize the advantages of its complex structure. 
The number of bones and muscles which enter into its 
formation impart to it a wide range of mobility which 
adapts it for the most delicate manipulations. The 
varying length of the fingers, and the manner of their 
articulation, enable us to grasp with ease and firmness 
objects of a spherical form. Similarly, their arrange- 
ment is conducive to the ease with which we can poise 



2A2 Summary 

on our finger-tips and thumb any flat surface, such 
as a plate. The numerous bones and joints in the hand 
are also of much service in reducing the violence of shocks. 
In striking a blow with the fist the force is much broken 
up and diminished in intensity before it reaches the bones 
of the fore-arm, so that we are enabled to strike power- 
fully without doing injury to ourselves. 

In conclusion it may be well to remind the reader that 
the form of the upper limb differs in the two sexes. As 
an artist of repute once said, 'A woman should have no 
anatomy ' ; this really is the gist of the .whole matter. In 
the female the bones are smaller and of more delicate form ; 
the muscles are less developed, and in addition they are 
covered by a thicker layer of subcutaneous fat which 
masks and softens the outlines of the underlying structures, 
imparting a roundness and fullness to the limb such as is 
characteristic of the sex (Pis., pp. 34, 36, 52, 54, 72, 86, 262, 
270. 298. 308, 438). In both male and female the form of the 
limb is tapering, its greatest thickness being in the region 
of the shoulder, where the deltoid muscle overlies the 
shoulder-joint. 

Another matter requiring consideration is the length 
of tlin limb. This will be more fully discussed when the 
question of proportion is considered ; but it may be well to 
state luTe that a short arm is much more pleasing than 
a long one, the latter being regarded as rather an ape-like 
characteristic, and one which is more frequently observed in 
the lower races of man. As Briicke has justly observed, 
• A model is not easy to find in whom the arms are too 
Hhort as compared with the legs, but there is no lack of 
specimens in whom they are too long.* 



CHAPTER IX 



THE GLUTEAL REGION 



Before passing to the consideration of the lower limb 
it may be well to refer to some of the points already- 
discussed in one of the earlier chapters. The essential 
difference between the upper and lower limbs of man was 
there described, and it was shown that the lower limb 
was designed to combine the functions of support and 
progression. 




Fig. 115. Diagrammatic represen- 
tation of the shoulder-girdle. 

a. First dorsal vertebra. 

h. First rib. 

c. Breast-bone (sternum). 

d. Shoulder-blade (scapula). 

e. Collar-bone '^clavicle). 

/. Humerus (bone of upper arm). 



Fig. 116. A diagrammatic repre- 
sentation of the pelvic girdle. 

a. Sacrum. 

ft. Haunch-bone (os innominatum). 

c. Symphysis pubis. 

d. Upper end of thigh-bone (femur). 



The attention of the student must be particularly directed 
to the arrangement of the bones which form the pelvic 
girdle, by means of which the lower limb is connected with 
the trunk. It has been already shown that the shoulder- 
girdle is movable on the trunk, for the upper limb is 
specially adapted to meet the requirements of free move- 
ment and prehension. In the case of the pelvic girdle, 

R 2 



o^^ Innominate Bone 

however, the bones afford support to the trunk, and for 
this reason the girdle-bones of the lower limb are firmly 
united to the axial skeleton. The only movements which 
are comparable in the two limbs are those which take 
place at the shoulder and hip joints. There is no move- 
ment between the pelvic girdle and the trunk resembling 
that which takes place between the shoulder-girdle as 
a whole and the trunk, or between the component parts 
of that girdle, viz. the collar-bones and shoulder-blades. 

On examining the skeleton, the gird-le-bones of the lower 
limb are seen to be firmly united with that part of the 
vertebral column of back-bone which is specially modified 
by the osseous union of its component vertebrae to form 
the sacrum [ante, p. 7). In front they are united by an 
immovable joint called the symphysis pubis. By this 
means an osseous girdle, called the pelvis, is formed which 
encloses or surrounds a very considerable cavity called 
the pelvic cavity. 

Leaving for the present the consideration of the pelvis, 
tlie portion of the girdle strictly associated with the limb 
may be examined. This consists of an irregularly shaped 
bono called the innominate or haunch-hone. Although in the 
adult this appears as a single bone, it is in realit}^ formed 
by the fusion of three separate parts. The student will 
have no difficulty in recognizing on the outer side of the 
haunch-bone a well-marked cup-shaped cavity called the 
acefahfdnin. Into this deep hollow the head of the thigh- 
bone fits. The acetabulum marks the point of coalescence 
of the three parts of which the fully developed bone is 
constituted. Extending forwards and inwards from this 
articular cavity is the pubis; passing upwards, outwards, 
and ba('k wards we note the expanded curved plate of bone 
callffl the iliufii; })olow and slightly bohind is the ischium. 
1 no pubis ainl iho ischium are further united by processes 
<'allGfl f lif.ir rnmi. and thus enclose between them a wide hole, 



I 



Skeleton of Lower Limb 



245 





Fio. 117. The skeleton of the lower Fig. iiS. The skeleton of the lower 
limb as seen from the iront. limb as seen from the outer side. 

a. The sacrum. rf. Knee-pan (patella). 

h. The haunch-bone (os innominatum). e. Outer bone of leg (fibula) 

c. Thigh-bone (femur). /. inner bona of leg (tibia). 

Q. Bones of foot. 



246 



Innominate Bone 



called the thyroid or obturator foramen, which lies in front of 
and below the acetabular articular cavity above mentioned. 
With parts only of this irregularly-shaped haunch-bone are 
we immediately concerned, and with some of these details 
the reader is already familiar, as reference has been pre- 




Fio, 119. Ilauncli-bone (03 in- 
noniinatum) of male seen from the 
outer side; it is represented as 
articulated with the sacrum. 



Fig. 120. Haunch-bone (os in- 
nominatum) of female. Note that 
the female bone is more tilted for- 
ward than the male, as shown by 
the relation of the points *• and e 
to the dotted vertical line. 

/. Anterior inferior iliac spine. 
(J. Acetabulum (hollow for heiid of thigh- 
bone). 
i. Posterior superior iliac spine. 
j. Spine of ischium. 
I. Tuberosity of ischium. 
«. Si)ine of pubis. 

viously inadf5 to them in the description of the abdominal 
walls and Hanks (ante, p. 67). Thus the upper border or 
crent of the expanded iliac bone has been already studied 
in iU relation to the surface. This describes a sinuous 
curve, l>einfr towards the outer side convex in front and 
concavb behind, whilst between its two extremities the 



a. niac iK>rtion of the innominate bone. 

b. Pubic pjrtion of the innominate bono. 

c. I«rhial portion of the innominate 

bone. 

d. Iliac crest. 

«. Anterior auperior iliac spine. 



The Ilium 



247 



crest is arched in a vertical direction, the convexity of the 
curve being inclined upwards. The extremities of this 
crest, called respectively the anterior and posterior superior 
iliac spines, have been noted as important determinants of 
surface form, the anterior corre- 
sponding to the depression at the 
outer side of the fold of the groin 
(ante, p. 68j, the posterior under- 
lying the depression or dimple 
which is so characteristic a feature 
of the lower part of the back in 
both the male and female [ante, 

P- 45)- 

The anterior two-thirds or so of 

the inner surface of this plate-like 
bone is hollowed out to form the 
iliac fossa. This affords an ex- 
panded surface for the support of 
the abdominal contents and for the 
attachment of the iliacus muscle. 
The posterior third of the inner 
aspect of the ilium is rough and 
irregular, and is adapted for articu- 
lation with the side of the sacrum, 
to which it is firmly united. This 
surface corresponds to the posterior 
part of the crest, which curves 
slightly outwards. The outer sur- 
face of the ilium furnishes an ex- 
tensive attachment for the muscles 

of the buttock, which, in man, attain a remarkable develop- 
ment, and are intimately associated with the maintenance 
of the erect position. 

Of the pubis we are concerned only with the anterior 
part or body. It is by means of this bone that the inno- 




FiG. 121 (after Richer). 
Shows the relation of the 
iliac furrow to the iliac crest. 



2^8 Th^ Pubis 

minate or liaunch- bones of the two sides articulate witli 
each other, forming a joint which is known as the sym- 
physis pubis ; in this way the osseous girdle is completed 
in front. This joint lies in the middle line in continua- 
tion with the direction of the median furrow which runs 
down the front of the abdominal wall. On each side of 
this lie the bodies of the respective pubic bones, occu- 
pying the interval between the inner extremities of the 
folds of the groin on either side. Owing to the thick pad 
of fat which overlies these bones, their outline is concealed, 
but they assist, however, in forming the general round- 
ness which is so characteristic of this region. If the finger 
be passed along the upper border of the pubis from the 
symphysis outwards, one can easily recognize the presence 
of a well-marked process called the spine of the pubis. To 
this point attention has been already directed (ante, p. 68j 
when describing the lower limits of the anterior abdo- 
minal region. It affords attachment to an important band 
called Poupart's %ame»^, which stretches obliquely upwards 
and outwards, to be fixed to the anterior superior iliac 
spine (the anterior extremity of the iliac crest). It is 
this ligament, as has been seen, which corresponds to the 
position of the furrow of the groin. The upper border of 
the body of the pubis between the symphysis and the 
spine is called the crest of the pubis. 

The ischium as a rule does not directly influence the 
surface form. The most prominent part of that bone, which 
lies below and slightly behind the acetabulum, or articular 
cup, is thick and rounded, and is called the tuberosity. In 
the standing position the tuberosity is covered by the thick 
fl"shy fihres of one of the great muscles of the buttock, the 
yluteuM luaximus, but when the leg. or more properly the 
thi^h, is bent forward at the hip-joint the muscle slips 
over this bony prominence, and so uncovers it. Thus, in 
tho sitting posture, the tuberosity of the ischium underlies 



The Sacrum 249 

the skin, and it is on these prominences that the body weight 
rests, so that the muscles are in no way crushed or com- 
pressed in this position. Further, provision is also made 
to relieve, as much as possible, the parts from pressure, 
for the fat overlying the ischial tuberosities is abundantly 
mixed with fibrous tissue which imparts to it a highly 
elastic quality, resembling, in this respect, the arrange- 
ment met with in the tissues underlying the heel. 

It is by the fusion of these three bones, the ilium, the 
ischium, and the pubis, that the innominate or haunch- 
bone is formed, and it is, as has been said, at the point of 
fusion of these three bones that the acetahulum is placed. 
We need for the present only compare it with the glenoid 
fossa on the shoulder-blade. The latter was seen to be 
relatively small and shallow, thus permitting great free- 
dom of movement and affording limited support, whereas 
the acetabulum is large and deep, and better adapted to 
furnish support, though less well fitted to allow free 
movement. The further details in connexion with this 
subject are reserved until the hip-joint is described. 

It is by the union of the two haunch-bones with each 
other in front, and the sacrum behind, that the pelvis is 
formed. The sacrum, as has been already explained [ante, 
p. 7), is a specially modified part of the vertebral column 
or back-bone, which is built up by the fusion of five verte- 
bral segments. It is, so to speak, wedged in between and 
behind the iliac portions of the two innominate bones, 
with which it is firmly united by immovable joints. 
In this way provision is made for the transmission of 
the body weight from the vertebral column downwards 
through the two haunch-bones, and so on to the thighs. 
The surface relations of the sacrum have been already 
studied {ante^ p. 45), and the student may be referred to 
that description for further details. Meanwhile, it will be 
sufiicient to note that it is only the posterior aspect of 



2^0 



The Pelvis 



this bone which is a determinant of the surface contours. 
The osseous girdle so formed encloses the pelvic cavity in 
which certain viscera are lodged. This cavity is described 
as consisting of two parts, the true and the false. The false 
pelvis corresponds to the hollow formed by the expanded 
iliac bones. The true pelvis is that part of the cavity which 
is bounded in front by the pubes, on either side by the 
ischia, and behind by the sacrum. 

The pelvis is a most important determinant of form, not 
only directly, as has been already sufficiently explained, 
but also indirectly, since by variations in its size and 
shape it influences the entire modelling of the lower part 
of the trunk and upper part of the thighs. It is on the 
width of the pelvis that the narrowness or breadth ot 
the lower part of the figure depends. These differences 
give rise to the characteristic figures of the two sexes. The 
cavity of the true pelvis in the female is, for sexual reasons, 
larger than that of the male, and thus necessarily reacts 
on the form of the bones which surround- it, leading to 
their greater expansion. It follows therefore that the 
female pelvis is wider than the male. On the other hand, 
the male pelvis, though narrower than the female, is deeper. 
These two facts account ibr the differences in the width 
of the iigure across the hips in the two sexes, and also 
for the circumstance that the flanks in the female are 
relatively longer than those of the male, for the iliac 
crests in the female do not rise to so high a level. The 
pelves of the male and female present many other differ- 
ences, but these need not here be discussed. 

Another matter of great importance in regard to the 
influence of the pelvis on the surface form is its position 
III n-latiou to other parts of the skeleton. The student will 
••xpf;ri(;M(M considerable difficulty in acquiring a correct 
knowl.;dge of its usual position in the erect position, unless 
ho has access to a specimen which has been separated from 



The Pelvis 251 

the rest of the skeleton, and adopts some such simple rule 




Fig. 122. The male pelvis. 




Fig. 123. The female pelvis. 



a. Iliac portion of os innominatum. 
6. Pubic portion of os innominatum. 

c. Ischial portion of os innominatum. 

d. Iliac crest. 

e. Anterior superior iliac spine. 
/. Anterior inferior iliac spine. 



g. Acetabulum. 
h. Pubic arch. 
^^ Pubic symphysis. 
«. Spine of pubis. 

The sacrum is seen wedged in between 
the two innominate bones behind. 



as the following: — Take the pelvis and hold it in such 



-3- 



Faslus ex f emus.. ^ 
Band of Richer. 

Reclus fcmoris " " 

tendon. 
Patella. " 

Ext. condyle- 

Lig. patellae: 

Ilio-tib.band:' 
I lead of fib. 

B urps. short '- 

head. 
Popliteal space. 

Gastrocnemius: 
Soleus, - ' 
Tibialis ant.-' 
Peroneus long: 
Long ex t.of toes". 
Peroneus brevis. 
Long exLof gt. toe.- - - 
'Pendo A chillis, 
A nnular lig. 
lixl b rev. digit. 



Peroneus tertius.' Peroneus brev. 

25 Sartorius. tendoti. 

26 Seniitendinosus, tendon. 

27 Gastrocnemius, inner head. 
2H Tibia, subcutaneous surface. 
2li Soltus. 

^^Trndo A chillis. 

31 J- lex or longus digitorum pedis. 

32 Vibialis anticu? tendon. 
3:i Intrrnal malleolus (tibia). 
M Internal annular ligament. 
X^Abductor of great toe, 

30 Os calcis. 



^External oblique. l(\y 

2 Erector spinae, 

3 Iliac crest. 

4 Rectus femoris 

5 Tensor fasciae fern 

6 Gluteus medius. 
*li Trochanter major. 

8 Ilio-tibial band. 

9 Biceps cruris, long head. 

10 Gluteus maximus. 

11 Senii-tendinosus. 
VlAddtictor inagnus. 

13 Gracilis. 

14 Rectus femoris. 

15 Semi-membranosus. 

16 Senii-tendinosMs. 

17 Sartorius. 

18 Vastus internus. 

19 Gracilis, 

"iS) Band of Richer, 
21 Patella. 
Tl Fat. 

23 Popliteal space. 

24 Ligpat. 



,i'-i' 



.33 






The Pelvis 253 

a position that the two anterior superior iliac spines 
(anterior extremities of the iliac crests) lie in the same 
horizontal line, then move the bone till the s^^mphysis 
pubis lies vertically beneath the centre of the line which 
connects the two anterior superior iliac spines ; or, draw 
a horizontal line on any vertical surface, a wall for instance, 
and place the pelvis against this vertical surface so that all 
three points (the two anterior superior iliac spines and 
the symphysis) are in contact with it at once, care having 
been taken to place the anterior superior iliac spines on 
the horizontal line already drawn. The bone will now 
lie approximately in the position which it occupies in the 
living when we stand upright. As a matter of fact its 
upper part is slightly tilted forwards in the female, whilst 
in the male this part of the bone is tilted a little backwards. 
This variation in the obliquity of the position of the pelvis 
is associated with very remarkable changes in the contours 
of other parts of the figure, and its further description must 
be delayed until the anatomy of the hip-joint has been 
considered ; it is on the adjustment of this articulation that 
the alterations in position or ' obliquity ' largely depend. 

The relation of the width across the hips and that across 
the shoulders is a point requiring some consideration. In 
both sexes the former is less than the latter, though in the 
female the difference between the two measurements is 
much less than in the well-proportioned male. In other 
words, women have broad hips and narrow shoulders, whilst 
men have broad shoulders and narrow hijDS. This difference 
in hip-width is largely dependent on the fact that in women 
the pelvic width is not only relatively, but also absolutely, 
greater than in man. Since this hip-width includes the 
upper extremities of the thigh-bones as well as the trans- 
verse diameter of the pelvis, it will be necessary to say 
more about it after we have described the anatomy of the 
* thigh-bone. 



254 The Femur 

The thigh-bone or femur (Figs. 124-126) in man is 
remarkable for its great length. Like other long bones, it 
is described as possessing a shaft and two extremities. In 
connexion with the upper end of the bone the head must 
be studied. This consists of a rounded knob, forming about 
two-thirds of a sphere, which in the living is covered with 
a layer of articular cartilage and fits into the deep socket 
of the acetabulum on the outer side of the haunch-bone. 
This rounded articular head is supported by means of 
a process called the neck^ by which it is united to the 
upper extremity of the shaft, forming with, it an angle of 
about 125°. This angle varies according to circumstances ; 
it is more open in children, more acute as age advances, 
and is usually less obtuse in the female than in the male. 

The length of the neck of the bone is a matter of great 
importance, as it permits of a freer range of movement at 
the hip than would otherwise be the case, considering the 
depth of the articular cup and the prominence of its borders ; 
further, it acts as a lever for the muscles which control the 
movements of the hip-joint, and which are inserted around 
the neck where that part of the bone becomes fused with 
the shaft. At this point there are two well-marked pro- 
cessfs developed : these are called the trochanters. They 
are distinguished by the names great and small ; the small 
or IpHHP.r trochanter is placed on the lower side of the neck 
as it joins the shaft, and is of little interest from our 
standpoint. 

'I'hn great trochanter is situated at the upper and outer 
side of the angle formed by the fusion of the neck and 
shaft, and overtops, as it were, the root of the neck. This 
process is of the greatest importance as a determinant of 
surface form, since its outer aspect is merely covered by 
skin, fat, and certain thin, though strong, tendinous layers. 
It ran ])o readily felt, and its prominence assists in im- 
parting to the hips tliat width to which attention has been 



The Femur • 255 

already directed. As a rule it corresponds in position to 
the greatest width of the male figure in this region ; most 
frequently in the female the greatest breadth is at a some- 
what lower level, owing to the presence of the subcutaneous 
fat which tends to accumulate along the upper and outer 
part of the thigh. It is into the trochanter major that 
many of the muscles concerned in the maintenance of the 
erect position are inserted. 

The shaft of the thigh-bone is seen to be curved when 
viewed from the side (Fig. 125), the convexity of the curve 
being directed forwards. Though covered with muscles, the 
bone yet exercises a considerable influence on the form of 
the limb, and it is to this forward curve of the shaft that 
the rounded form of the front of the thigh is in part due. 

On the hollow side of the curve, i. e. on the back of the 
bone, the shaft is strengthened by the addition of a rough 
ridge called the linea aspera. Besides imparting increased 
rigidity to the bone, this ridge affords extensive attachment 
to muscles. 

Interiorly the lower end of the bone is expanded, forming 
two processes, called the condyles. These are coated with 
articular cartilage and enter into the formation of the knee- 
joint. They will be more fully described when the anatomy 
of that joint is considered. 

The position of the thigh-bone in the limb is oblique. 
This may be easily demonstrated. When we stand in the 
military position of attention, the knees are close together, 
whilst the upper extremities of the thigh-bones are separated 
by the pelvic width between the two acetabular hollows. 
According as the interval between the heads of the thigh- 
bones is increased or diminished, so the obliquity of the 
shaft is rendered greater or less. This explains how it is 
that the thigh-bones of women are usually more oblique in 
their position than those of men, because superiorly they 
are separated by a pelvis of greater width, whilst inferiorly 



2^6 



The Femur 




I'lO. 124. Front view 

n. H..„.|. 

ft. TrfMlifiiifcr iiiftjor. 

C Tr«K-hftnt/nr minor. 

«. Kxt«rtial 'ori'Iylo. 



Ri>ht thigh-bone (femur). 

Fia. 125. Outer side. Fig. -126. Back view. 

/. Articular surface of condyles. 

rj. rntercondyloid notoli. 

h. Surface for attachment of gluteus 

maximus. 
i. Internal condyle 



Obliquity of the Thigh-bones 



257 



they touch each other at the knees. It is this greater 
obliquity of the femur in women which gives rise to the 
knock-kneed appearance which is really a characteristic of 
the sex. When, from shortness of the thigh, this appearance 
is unduly pronounced, it becomes exceedingly offensive and 
unpleasant, but in its gentler form it often conveys a sense 
of delicacy and refinement. It is seldom, indeed, that the 
artist would be called upon to represent the female nude^ 





Fig. 127. 



Fig. 128. 



Diagrams showing the greater degree of obliquity of the thigh-bones 
dependent on the greater pelvic width in woman, Fig. 128, as compared 
with man, Fig. 127. 



with the limbs placed as has just been described, i. e. the 
position in which the knock-kneed appearance is most 
pronounced : more usually one or other knee would be 
advanced and slightly bent, an action sufficient to impart 
to the figure a sense of grace and modesty. As a result 
of the greater obliquity of the thigh-bone in women it 
follows that the angle formed by the n€ck of the femur 
with the shaft is more acute than in the male. 

The hip-joint lies so deeply embedded on all sides in 



258 



The Hip-joint 




fleshy muscles that it has but slight influence on the surface 
form. It is only when the limb is thrown as far back as 
possible that the head of the femur pushes forward the soft 
parts which overlie it, and thus leads to the obliteration 
of that depression on the upper and anterior aspect of the 
limb called the hollow of the thigh. 

The surfaces of the joint fit so accurately that atmospheric 
pressure is alone sufficient to keep the smooth rounded 

articular head of the femur in contact 
with the hollow of the acetabulum. 
This has been demonstrated experiment- 
ally, after death, by cutting away all 
the muscles and ligaments ; under these 
circumstances the articular surfaces of 
the bones still remained in contact 
instead of falling away, as one might 
expect. 

The socket of the acetabulum, further 
deepened by a ligament which sur- 
rounds its edge, affords ample support 
to the head of the femur, through which 
the weight of the trunk is transmitted. 
The joint is a very strong one. This is 
partly due, as above stated, to the form 
of its articular surfaces, but is also 
dependent on the strength of the liga- 
ments which bind the bones together. 
One frequently hears of dislocations of the shoulder-joint, 
but displacements of the hip-joint are of rarer occurrence 
and are generally the result of much greater violence. 

Tho capsule of the hip-joint is formed of dense fibrous 
tiHsuo. h, certain situations it is much thickened and 
forms wcll-inarkod fibrous bands, which are described as 
tho li^ramonts of the joint and have received special 
flie most important of these is one which passes 



Fio. 129. Diagram- 
matic section through 
the hip-joint. 

a. Tlie tliick black lines 
ruprfiBpnt the carti- 
lajfo- covered articular 
Burfarcs. 

'*. Th«; joint cavity. 

c. Tho lifi^aments around, 
fomiirifj tho capsule, 
the int«Tior of which 
is linod hy synovial 
momhrano reprcsont- 
t'<l hy dotted linos. 



names. 



Ilio-femoral Ligament 



259 



down iu front of the articulation ; it is called the ilio-femoral 
ligament^ or, from its resemblance to an inverted X (Y), 
the Y-shaped ligament. This is attached to a part of 
the ilium immediately above the acetabulum, called the 
anterior inferior iliac spine, and spreading out inferiorly 
in a fan-shaped manner, it is united to the thigh-bone 
below along a rough line, called the spiral line, which 
marks the point of fusion anteriorly of the neck of the bone 
wdth the shaft ; superiorly this 
line is carried up along the inner 
and anterior border of the great 
trochanter. 

Great importance attaches to 
this ligament, because it prevents 
excessive extension backw^ards of 
the thigh on the trunk ; it has 
been already pointed out that one 
of the characteristics of man is 
the fact that he alone of all four- 
footed animals can place the thigh- 
bone in such a position that the 
axis of the limb falls in line w^ith 
the axis of the trunk. Any further 
range of movement beyond this is 
checked, however, by the tighten- 
ing of this ligament. 

It is mainly owing to the 
presence of this ligament that man can stand erect for 
prolonged periods without experiencing much muscular 
fatigue. "When we stand upright, the line of gravity passes 
behind the axis of the hip-joint and the points of attach- 
ment of this ligament ; thus, that force in this position is 
constantly acting so as to keep the ligament tense and 
stretched, thereby mechanically locking the joint; no 
special muscular effort is required to effect this purpose, 

s 2 




Fig. 130. Diagram show- 
ing the attachment of the 
ilio-femoral ligament, 

a. Ilium. 

b. Anterior superior iliac spine. 

c. Anterior inferior iliac spine. 

d. Ilio-femoral ligament. 
6. Pubis. 

/. Symphysis pubis. 

g. Femur. 

h. Sacrum. 

i. Tuberosity of ischium. 



26o 



Mechanism of Erect Posture 



^i 



s 



Kio. 131. Diajjram to 
nIiow how thf figure is 
h«'I»l eriM-t, 

Tho thick l)l.i(k linos in- 
dicAt« tho prin( ipal imiscles 
therein coiwcriu-d. Tho vor- 
tlcAl ilotu-d lino imlicates the 
dirvctinn «!Xit«mh«iI by tho 
forri, of urHvity. Not„ that 
«)ii» fiilla U.hind tho axis of 

'"'"' ' tho hip nnd in 

'■ '• "I til.. knc(., thiiH 

'• '• rmo til., litjiimcfnts 

"• "t«, which uro rn- 

I' • "" th« tlifiinj by 

dotl«Hi lin«f« pfuuitnK in front 
"f tho hip (ilio-foujorHl) nnd 
lM>hin«i th« know (iHjHtorior 
liK'uiu'iiti. 



hence we do not suffer from the 
fatigue which would be involved by 
a constant and prolonged muscular 
strain. 

The student may satisfy timself 
as to the correctness of these observa- 
tions by making a little experiment. 
He will find that he can stand in the 
military position of attention for a 
long time with little discomfort and 
fatigue. If, in this position, the 
hands be placed on the buttocks and 
back of the thighs, the muscles of 
these regions will be found flaccid, 
or but slightly contracted, but if the 
body be now bent forward at the hips, 
so as to throw the line of gravity in 
front of these joints, he will find it 
impossible to maintain this position 
for long without becoming tired. On 
passing the hand along the back of 
the thighs and over the buttocks he 
will now recognize that the muscles 
are powerfully contracted, particu- 
larly in the former situation. The 
movement of the hip is no longer 
mechanically checked by the action 
of the ligaments, but is controlled 
by the contraction of the muscles 
situated in the aforesaid regions, 
which is the explanation why this 
])Osition cannot be maintained for 
any length of time without a sense 
of muscular fatigue. 

Slight variations in the length of 



Obliquity of the Pelvis 261 

this ilio-femoral ligament occur in different individuals. 
These variations are attended with very remarkable differ- 
ences in the contours of the figure. A slightly longer 
ligament will naturally allow of a greater range of extension 
of the 'thigh on the pelvis; on the other hand, when the 
ligament is short, the range of movement in a backward 
direction will be less. 

Interpreted in another way, this means that when we 
stand erect with the thigh-bones in a more or less vertical 
position it follows that the pelvis, which they support on 
their upper extremities, will be tilted forwards or back- 
wards according as the ligament is short or long ; this 
variation in the position of the pelvis consequently leads to 
alterations in its obliquity. Under ordinary circumstances, 
the plane formed by the inlet of the true pelvis, represented 
by a line passing across from the upper part of the symphysis 
pubis to the point where the lowest lumbar vertebra unites 
with the upper part of the sacrum, usually forms with the 
horizon an angle of from 60° to 64°. If the pelvis be tilted 
further forwards, as is the case when the ilio-femoral ligament 
is short, the obliquity of the pelvis is thereby increased, whereas 
if the ligament be long the pelvis will lie in such a position 
that the plane of its inlet more nearly approaches the hori- 
zontal : in the latter case, therefore, the obliquity of the 
pelvis is diminished. In using the expression ' obliquity 
of the pelvis ' we refer to the obliquity of the plane of its 
inlet ; the position of the entire pelvic girdle is, however, 
necessarily involved, as its component parts are immovably 
united, and variations in this obliquity will obviously be 
associated with alterations in the relative position of the 
pelvic girdle to other parts of the skeleton. 

A little consideration will enable the reader to realize the 
importance of the changes in form which are secondarily 
dependent on these alterations in the position of the pelvis. 
The back of the pelvic girdle is formed by the sacrum, 



262 Obliquity of the Pelvis 

and the position of this bone accordingly alters as the 
entire pelvis is tilted forwards or backwards; thus, if 
tilted backwards, the posterior surface of the sacrum (that 
part of it with which we are most concerned as a 
determinant of surface form) will more nearly approach 
the vertical, whereas a forward tilt of the pelvis will 
cause this surface to incline more obliquely, the axis 
of the bone being directed more backwards. But the 
sacrum, formed, as the reader is aware, by the fusion 
of several segments of the back-bone, is connected above 
with the movable part of the vertebral column. If 
now the sacrum, and with it the pelvis, be tilted 
ibrwards, so that the upper extremity of the sacrum is 
thrown further in front, it follows that the bones of the 
vertebral column, with which it is connected, must be 
bent forward too. As it is however necessary, for the 
maintenance of the erect position without muscular fatigue, 
that the line of gravity should pass through the column 
at certain points, and fall in definite relation to certain 
joints, it also follows that this forward thrust of the entire 
column must be compensat'ed for by the development of 
more strongly marked curves. This is what takes place, for 
in pei*sons where the pelvic obliquity is great, i. e. where the 
pelvis is much tilted forwards, a condition which, as has 
lioen said, is largely dependent on the existence of a short 
ilio-ienioral ligament, the curves of the back, particularly 
tli(3 lumbar curve, are more strongly marked, and the 
projection of the buttocks is more pronounced ; whereas in 
iiidividuuls in whom the pelvic obliquity is slight, i. e. in 
p<T8ons who possess a long ilio-femoral ligament, the curves 
of tho back are but slightly emphasized, as here the 
nect-ssity for strongly marked compensatory curves does not 
ariHo. These facts may perhaps be better understood by 
relercnco to the accompanying diagrams: Fig. 132 repre- 
»eut8 a ff'inah) (iguro with well-marked pelvic obliquity 



Pelvic Obliquity 



263 



and pronounced curves in the back, Fig. 133 is that of 
a male in whom the obliquity of the pelvis is less, and 





Fig. 132. 



Fig. 133. 



Figs. 132, 133, show the influence of the pelvic obliquity on the 
figure of the male and female. In Fig. 132 the female pelvis ia tilted 
further forward than in the male, Fig. 133, as will be seen by noting the 
position of the anterior extremity of the iliac crest (anterior superior iliac 
spine). As a result of this the lumbar curve is more pronounced in 
Fig. 132 than in Fig. 133. This reacts on the outline of the figure, the 
curves being more pronounced in the female than in the male. 

as a consequence the back appears much flatter than in 
Fig. 132 (see also Figs. 119, 120, p. 246; also PI., p. 54, 
262, 278, 438;. 



264 Influence of Pelvic Obliquity on Thigh 

This difference in the pelvic obliquity reacts on the form 
of the thigh as well as on the trunk, for if the obliquity of 
the pelvis be increased the anterior superior iliac spines 
(the anterior ends of the iliac crests) will be thrust forward, 
so as to lie on a plane anterior to the plane occupied by the 
symphysis pubis. Under these circumstances, the most 
prominent border of the thigh above will correspond to the 
anterior superior iliac spine, and the anterior surface of the 
limb will slope slightly inwatds and backwards towards the 
symphysis pubis ; whereas, when these several bony points 
lie in the same vertical plane, or when the anterior superior 
iliac spines lie in a plane behind that of the pubic sym- 
physis, the surface of the thigh between these two points 
will be directed forwards, instead of forwards and inwards* 
as in the former case. The same thing may be expressed 
differently by saying that, in the former condition, the 
pubic symphysis is withdrawn between the thighs, and 
overhung by a more prominent abdominal curve, whereas, 
under the latter conditions, the symphysis lies on the same 
plane with the fronts of the thighs, and is less overhung 
by the abdommal curve (Pis., pp. 72, 86, 216, 298, 434, 438). 

The artist will of course be guided in his selection of 
models by a reference to these points, avoiding, as far as 
possible, extreme conditions, and recognizing that the most 
pleasing results are obtained when the average is repre- 
sented, thougli ho will not fail to observe that in the female 
one meets with degrees of obliquity which, if represented 
in the male, would be altogether out of character with the 
type. Ho may note, as a more or less definite rule, that 
in the female, the anterior superior iliac spines lie slightly 
ill advance of the symphysis pubis in the erect position, 
and tliat in the male they lie either on the same plane or 
slightly behind the symphysis (Figs. T19, 120, p. 246). 

Tho movements of tlui liip-joint must next be con- 
sidered. Flexion is tho, movement whereby the thigh is 



Movements of the Hip- joint 265 

bent forward on the trunk ; this movement is limited by 
the approximation of the anterior surface of the thigh to 
the front of the abdomen. It is worth noting that the 
range of this movement is affected by the position of the 
knee. When that joint is bent, we can ilex the thigh 
on the trunk until their surfaces come into contact ; when 
the knee is straight or extended, jflexion at the hip is much 
more limited in its range, and is arrested by the stretch- 
ing of the muscles called the hamstrings on the back 
of the thigh. This is at once apparent when we touch, 
or attempt to touch, the toes without bending the knees 
(see p. 306). 

Extension, as has been said, is remarkably free in man, but 
a word or two is necessary to prevent any misconception 
regarding the range of this movement. When the thigh 
is brought into line with the axis of the trunk the movement 
is checked by the ilio-femoral ligament, and no further 
movement is possible in this direction ; how comes it then 
that we can touch the ground behind us with the foot? 
In order to understand how this takes place, we must 
consider the movement which takes place at the hip-joint 
of the opposite limb to that which touches the ground 
behind us. The reader may best recognize the move- 
ments which take place by studying them in his own 
person. If he stands with the toe of the right foot touching 
the ground about a couple of feet behind the heel of the 
left foot, upon which he is resting the weight of the body, 
he will note that the trunk is thrown forward, and the right 
leg is directed backward in line with the axis of the trunk, 
i. e. in the condition of full extension. Under these con- 
ditions no change in the relative position of these two parts 
of the body has taken place; but if now he ^examines the 
condition of the left hip he will observe that the joint is 
in a state of flexion, and it is the combination of flexion 
of the left hip-joint with extension of the right thigh that 



266 Movements of the Hip-joint 

enables him to pass the right leg behind the point through 
which the line of gravity of the body falls. 

Fig. i3_j. will at once make this clear. 

The other movements which take place at the hip-joint 
are movements of adduction, or crossing the legs, and 
abduction or separating the legs. Rotation of the entire 
limb also takes place at this joint: it is the movement 
whereby we turn the point of the foot in or out. Circum- 
duction is the combination in sequence of the foregoing 
movements, either from within outwards or from without 

inwards. The several move- 

\ments are checked in most 
instances by the action of 
ligaments, or else by the con- 
tact of the neck of the thigh- 
_ ' bone with the margin of the 

acetabulum. 

In considering the muscles 
which effect these movements 
the reader must bear in mind 
one important difference be- 
tween the girdles of the 
upper and lower limbs. In 
Pi,} ,2 1 connexion with the former 

we studied a number of 
iiiuscirs which passed from the trunk and were inserted into 
the bones of the shoulder-girdle; by the action of these 
iniiscles the shoulder-girdle was moved upon the trunk. 
In consi(lf3ring the musculature of the pelvic girdle we 
have no such group to examine, as, for reasons which 
have {ante^ p. 243) been elsewhere fully stated, the pelvic 
«irdlo is immovably united with the axial skeleton of the 
trunk; hcnco the examination of the muscles which control 
tho movomonts ollh.; hij, may boat once proceeded with. 
I Ik- ij/ufrns nni.riiuus, or great musclo of the buttock, has 




Gluteus maximus 267 

an extensive origin from the posterior fourth of the iliac 
crest of the haunch-bone, from the aponeurosis covering 
the erector spinae muscle, from the side of the lower part 
of the sacrum, from the side of the coccyx, and from the 
surface of a ligament which stretches from the sacrum 
to the ischium, called the great sacro-sciatic ligament. 
A consideration of these attachments will enable the reader 
to realize that the origin of the muscle corresponds pretty 
accurately to the side of the V~shaped interval, at the 
root of the back, which separates the prominences of the 
buttocks behind, the upper and outer limits of which are 
marked by the presence of little hollows or dimples over- 
lying the position of the posterior superior iliac spines (the 
posterior extremities of the iliac crest), whilst the lower 
angle corresponds to the cleft between the buttocks. 

From this attachment the fibres pass outwards, forwards, 
and downwards, forming a thick fleshy sheet of muscle, 
which is inserted in front into a broad tendinous aponeurosis. 
All the fibres of the upper half of the muscle, together with 
the superficial fibres of the lower half, are inserted by means 
of this strong aponeurosis into the dense fascia which runs 
down along the outer side of the thigh. The bulk of the 
fibres of the lower half of the muscle, except the superficial 
ones above mentioned, are attached by means of a flattened 
tendon to a rough ridge, called -the gluteal ridge^ on the 
back of the upper third or fourth of the shaft of the thigh- 
bone; the latter insertion is entirely concealed by the 
former. It is the attachment of this muscle to the fascia 
of the thigh which gives rise to the most marked changes 
in the surface form (Pis., pp. 34, 38, 52, 54, 94, 98, 126, 
162, 182, 252, 268, 278, 318, 338, 366). 

In the erect position the fleshy fibres are seen becoming 
tendinous behind the line of the great trochanter and shaft 
of the thigh-bone, so that the outer surface of the great 
trochanter is merely covered by the aponeurotic insertion of 



268 Gluteus maximus 

the muscle, and not by its fleshy fibres. This fact is easily 
ascertained by placing the hand over the trochanter when 
in the upright position ; under these conditions the outline 
and form of the trochanter can be readily recognized; further, 
if the muscle be thrown into a powerful state of contraction, 
the prominence of the trochanter will be still more em- 
phasized by the tension of the aponeurotic layers over it, 
and the consequent hollowing out of the surface form behind 
it caused by the retraction of the fleshy fibres of the muscle 
(Pis., pp. 44, 50, 52, 54, 86, 318, 338). 

Tlje upper border of the muscle describes a curved outline, 
the convexity of which is upwards. Its general direction is 
indicated by a line drawn from a point a little in advance of 
the posterior superior iliac spine downwards, outwards, and 
forwards to the tip of the great trochanter. The outline 
of the lower border of the muscle is also curved, with 
the bend directed downwards across the back of the, thigh. 
The highest point of this border corresponds to the cleft 
between the buttocks, whilst its lowest extremity reaches 
a level corresponding pretty closely to the middle of the 
outer side of the thigh (i. e. the distance from the iliac crest 
to^the knee) (Pis., pp. 50, 52, 54, 86, 126, 318, 338). 

The oblique direction of the lower border of the muscle 
is a matter of some importance, as there has been a tendency 
to ascriljo the direction of the transverse furroio of the buttocJc, 
or the gluteal fold as it is sometimes called, to the influence 
of this border of the muscle. It will be evident that this 
cannot bo so, as the direction of the former is transverse, 
whilst the latter is oblique. As a matter of fact, the 
gluteal furnnv is a skin fold the depth of which depends 
on the degree of extension of the thigh on the trunk, and 
tlio quantity of fat present over the inner and lower aspect 
of the gluteus maximus muscle (Pis., pp. 34,36. 52, no, 142, 
182, 262, 268). 

The glulou.s maximus muscle is entirely superiicial, but 



4 



Gluteal Fold 



26g 



as it is alwa3^s overlain by a fatty layer of considerable 
thickness the outline of the muscle is much masked 
thereby, and the surface form therefore more rounded. 
The fat is most abundant on the back of this region, being 
much reduced in quantity as it passes forward over the side 
of the thigh. In the female the layer of fat is much thicker 
than in the male, so that we have less evidence of the form 
of the subjacent structures. For the same reason, the 
gluteal fold in women is more strongly mcirked, and of 
greater length transversely than in the 
male, whilst the overhang of the gluteal 
projection is in them more pronounced 
(Pis., pp. 36, 52,54, 142, 262, 268, 318, 338). 
It may here be noted that the sharp- 
ness of this fold varies according to the 
position of the limb ; it is always best 
marked when the limb is fully extended, 
i. e. straightened on the trunk, whilst 
it undergoes gradual obliteration with 
the bending of the thigh. Coincident 
with this movement, and the disappear- 
ance of the sharp transverse furrow, we 
note the tendency to an increase in 
the obliquity of its direction, so that it 
overlies, and more directly corresponds 
with, the oblique lower margin of the gluteus maximus. 
This difference is clearly seen in Fig. 135, and is readily 
apparent when we view the figure in profile in the erect 
and stooping positions ; in the former attitude the back of 
the thigh is abruptly separated from the buttock by a well- 
defined furrow, caused by the overhang of the gluteal region 
(Fig. 136), whilst in the latter position the flow of the line 
of the back of the thigh is continued into the contour of the 
buttock by a very open angle, or put in another way, this 
means, that the furrow which separated the two regions has 




Fig. 135. 



270 



Gluteal Fold 



now all but disappeared (Fig. 137, and Pis., pp. 34, 44, 
252. 268, 270). 

It sometimes happens that, in the male, the gluteal fold. 



'' // 



Fifj. 136. 




Fir,. 137. 



in placf. of })ninp; siuolo, is double. As such it is only seen 
whon tho limb is fully extended (Pis, pp. 52, 94, 98). 

Suporiorly. the disposition of the fatty layer over the 
filut/^UH mjiximus is dilfcrout in the two sexes. In women 
the fat forma a thick i)ad, which passes over the iliac 



The Buttock 271 

crest in front of the posterior superior iliac spine (i. e. the 
posterior extremity of the iliac crest), and thus becomes 
continuous with the fatty layer which covers the back and 
side of the flank. In this way the surface forms of 
the flank and buttocks are blended in one uniform contour ; 
we have no such definition of these regions as we see in 
the male, in whom the iliac crest is more or less apparent 
throughout its entire extent as a surface furrow (see Pis... pp. 
34, 36, 52, 54, 86, no, 142, 268). 

The female back is much less ' cut up ', by the indications 
of bony and muscular structure, than is the male, and 
displays a much simpler and more rounded contour, owing 
to this peculiar disposition of the superficial fat (Pis., pp. 
34, 36, 52, 54, 142, 270, 278). 

Anteriorly, the fat of the buttock is distributed in a very 
characteristic way in the female. It tends to accumulate 
in considerable quantity on the outer side of the thigh, just 
below the trochanter. This circumstance accounts for the 
less marked prominence of the trochanter in the female, 
and also explains why the width of the figure, in the 
female, is usually greater at some little distance below the 
level of the trochanters than at the trochanters themselves. 
When in the female fat is present here in undue amount it 
imparts a clumsy and ungainly appearance to the limb, parti- 
cularly in certain positions, and models which display this 
tendency to any marked extent should be avoided. A slight 
fullness, however, below the trochanters is not unpleasant, as 
it conduces to a more rounded form of the limb and gives a 
better outline to the outer side of the thigh. The student 
should be warned against the ungainly forms which are 
dependent on the undue accumulation of fat in the region 
overlying the iliac crest. This is particularly liable to occur 
in female models past their prime, and imparts a grossness to 
the form at variance with the delicacy and refinement dis- 
played in earlier life (Pis., pp. 34, 36, 52, 72, 278, 298, 434). 



272 Actions of Gluteus maximus 

The gluteus maximus muscle is a powerful extensor of 
the hip-joint. It straightens the thigh on the trunk when 
the hip-joint is bent. It acts in one or other of two ways 
or by a combination of both. Thus if the thigh be flexed 
on the trunk this muscle extends the thigh-bone at the 
hip-joint, or if the trunk be bent forward on the thighs, as 
in the stooping position, it assists in straightening the figure. 

The muscle is thrown into a powerful state of contraction 
in such actions as springing, leaping, rising from a chair, or 
running upstairs or up an incline. It also comes into play 
in some of the movements of abduction and adduction, and 
likewise assists in external rotation of the thigh. 

The gluteus maximus muscle in man has attained a very 
remarkable development, and is, as has been just shown, 
largely concerned in straightening the body. The figure, 
when once erect, can be held in that position for lengthened 
periods by the mechanical locking of the hip-joint, without 
any marked voluntary effort, though a certain amount 
of muscular contraction is necessary to steady the joint. 

The importance of the insertion of the gluteus maximus 
muscle into the fascia of the outer side of the thigh must 
not be overlooked. As will be described hereafter, this 
fascia forms a thickened band which passes down to be 
attached to the bones of the leg below the knee. Through 
this process of fascia the gluteus maximus exercises an 
influence in supporting and steadying the knee when that 
joint is extended ; and its action, in the male at least, is 
demonstrated by its influence on the surface forms along 
the outer aspect of the thigh (Pis., pp. 54, 86, 318, 338). 

The relation of certain bony parts of the pelvis and thigh- 
bone to the mu.scle varies according to the position of the limb. 
Of these the most important, from the present standpoint, 
IS the r<;lation of the trochanter major to the fleshy and 
ifndinous parts of the muscle. In the erect position, the 
trochanter is covered merely by the tendinous aponeurosis 



Tensor fasciae femoris 273 

of the muscle, but if the thigh be flexed upon the trunk the 
trochanter glides backwards under cover of the fleshy fibres. 
The reader can easily prove this by placing the hand over 
the trochanter whilst standing up ; under these conditions the 
bone is felt to be quite subcutaneous, being covered only by 
skin and the dense aponeurosis ; if, however, the trochanter 
be felt when sitting down, the student will recognize that 
it is separated from the fingers by a greater thickness of 
tissue, a circumstance which is due to the fact that the 
process is now overlain by some of the fleshy fibres of 
the muscle (Pis., pp. 104, 252, 274). 

In like manner the tuberosity of the ischium (the hinder 
and lower part of the haunch-bone) is at times covered and 
at other times uncovered by the muscle. In the erect 
position the lower border of the gluteus maximus over- 
hangs the tuberosity of the ischium, but when the thigh is 
bent it slips over that process of bone and so uncovers it, 
causing it to lie directly beneath the skin and subcutaneous 
fat. As already stated, it is upon this part of the skeleton 
that we rest the weight of the body in the seated position, 
and thus avoid any pressure on the fleshy part of the 
muscle. It is only in such views as that of a kneeling 
figure seen from behind, or from the side, that the artist 
would have any reason to concern himself with the surface 
forms dependent on these processes of bone. Under the 
conditions just mentioned, the rounded angle which marks 
the limit of the gluteal region, within and below, is 
dependent on the surface projection caused by these out- 
standing processes of bone. 

The tensor fasciae femoris is the name given to a muscle 
which separates the region of the buttock from the 
anterior aspect of the thigh; it arises by tendinous 
fibres from the anterior extremity of the iliac crest, 
close to the anterior superior iliac spine. The fleshy 
belly of the muscle is short and of considerable thickness. 



274 



Iliac crest. 



An tenor sufK-rior iliac spine. 

Tensor JiiiCMc Jtmo is. 

Jieclus /eiiions. 



Cluteni medtus. 



CluUus maxtmus 




yastus intern us- 
/ J?ectus /evioris tendon. 

Vastus extern Its. 

Patella. 
-External condyle of femur. 

J ho- tibial bund. 
.Lmtmcntuni patellae. 
Jiead of fibula 
.Jiiceps cruris tendon. 
...Biceps cruris, short head. 
-._ Va^stiiS extern ns. 

Jiiceps cruris, long head. 

Gastrocnemius, outer head. 

Peroneus lougiis. 

Soleus. 

Tibialis anticiis. 
...Extensor loiigus digitontin pedis. 
...Peroneus bicvis. 

Teiido Acliillis. 
.Peroneus tertius. 
External malleolus f fibula J 

.Anterior annular ligament 
External annular ligament. 



^fctus fimons. 

iSurtonus. 



It\a< €rr\t. 

****' —f^ne, ,tuH ^ftnt. 

'^'•^ 1**11— Itmont 

•■—■■ '/I •a/'^iKi 



Vastus in tern us. 
I Patella 



Interval condyle of femur. 
Ligamenium patellae. 




. Semimembranosus. 

Semite ndi nosus 
Jjracths. 

Gastrocnemius, inner hedc 
Tibia 
..Soleus. 

.ytddtictor magnus. 
Rec/iis femons. 
.Vastus extemus. 
. I'astus tntemus 
Tendo A chillis. 
Internal malleolus ( tibta, 

Tibialis anticus tendon. 

Tendtms of tibialis f 

flexor longus i 

Jnlemal a\ 



'Hedus /emoris tendon. 



Head of fibula 
Jiufp'. <rum tendon 



Patella 



Ilio-tibial Band 275 

The fibres follow a direction downwards, and slightly 
backwards towards the front of the great trochanter of the 
thigh-bone, and reach about three inches below it. At this 
point the muscle becomes blended with the strong fascia, 
which forms a band along the outer side of the thigh 
(Pis., pp. 54, 58, 86, 104, 126, 162, 252, 274, 318, 338, 366). 

The reader will remember that the gluteus maximus has 
an extensive insertion into this process of fascia. The 
muscles of the thigh are invested by a sheath of fibrous 
membrane much in the same way as the limb is covered by 
a tightly fitting stocking. This covering is much thicker 
along the outer side of the limb, and it is this thickening of 
the fascia which forms the band called the ilio-tibial hand. 
This may be regarded as the conjoined flattened tendon of 
the gluteus maximus and tensor fasciae femoris. The former 
is inserted into it above and behind, whilst the latter is 
attached to it above and in front. Inferiorly the ilio- 
tibial band passes over the outer side of the knee-joint 
and is inserted into the external tuberosity of the tibia 
(one of the bones of the leg). In this way the two muscles 
above described exercise an important influence in sup- 
porting the knee-joint in the extended position (Pis., pp. 
54, 86, 318, 338). 

From the fact that the upper end of this band is connected 
with muscles both in front and behind, it follows that the 
traction exercised by the combined action of the muscles is 
kept in the direct line of the thigh. 

Superiorly, the gluteus maximus and the tensor fasciae 
femoris are separated by a V-shaped interval, the angle of 
which corresponds to a point two or three inches below the 
summit of the great trochanter. The sides of the V corre- 
spond to the posterior border of the tensor fasciae femoris in 
front, and the upper border of the gluteus maximus behind. 
Superiorly, this triangular area is limited by the curved 
margin of the iliac crest. This surface is overlain bj 

T 2 



276 



Gluteus medius 



a fascia which stretches over it, from the gluteus maximus 
behind, to the tensor fasciae in front. Under cover of this 
fascia, and occupying the whole of the interval described, is 
another of the gluteal group of muscles called the gluteus 
medius (Pis., pp. 44, 54, 86, 126, 162, 318, 338, 366). 

The gluteus medius is a fan-shaped muscle. Its superior 
attachment is spread over the outer surface of the iliac 
expansion of the haunch-bone, extending from near the 
posterior superior iliac spine behind to the anterior superior 
iliac spine in front. Inferiorly, the fibres are gathered 
into a flattened tendon which is inserted into an oblique 
line running downwards and forwards across the outer 
surface of the great trochanter. As this attachment lies 
below and between the anterior and posterior origins of 
the muscle, it follows that the anterior fibres pass down- 
wards and backwards, whilst the posterior pass downwards 
and forwards, to this insertion. 

The muscle, as has been said, occupies a superficial position 
in the interval between the tensor fasciae femoris and the 
gluteus maximus, but it is partly overlain both in front 
and behind by these muscles. 

The gluteus medius is a powerful abductor of the thigh, 
i.e. it draws the limb away from the middle line of the 
body, causing the separation of the legs as in standing 
sfrirlo-logs. The action of the muscle is still better seen 
if the log be raised from the ground; again, we bring it 
into j)lay if we stand on one leg and incline the trunk 
to the Hide over the supporting limb. The muscle varies 
in its af!tion according to the part used. If the anterior 
fibrc'H rontract, they will act as rotators inwards of the 
tliigli. whilst the posterior fibres will assist in turning 
tlif! thigh outwards. It plays an important part in the act 
of walking, as it supports the trunk on the limb which is in 
contact with the ground during the time that the opposite 
foot is uplifted. 



Anterior Superior Iliac Spine 



277 



The surface forms of the buttock vary much, according 
to the position of the limb. As has been already stated, 
the gluteal fold or line which separates the region of the 
buttock from the back of the thigh undergoes gradual 
obliteration as the limb is carried from the fully extended 
condition to one of marked flexion. Coincident with this, 
there is a pronounced infolding of the furrow of the 
groin, together with a deepening of the fold immediately 
beneath it which crosses the upper and inner aspect of 
the thigh, which lies slightly above and towards the outer 
side. Externally, the angle formed by the profile of the 





Fig. 138. 



Fig. 139. 



front of the limb with the side of the trunk corresponds 
to the position of the anterior superior iliac spine ; ac- 
cording to the amount of flexion so the direction of the 
lines meeting at this angle varies. A reference to Figs. 
J 38, 139, will make this clear. The fold of the thigh 
passes outwards across the front of the limb so as to 
fall below the level of the anterior superior iliac spine, 
whilst the furrow of the groin corresponds externally 
to that process. When the limb is only partially flexed 
the profile outline of the front of the thigh, at the angle 
formed with the side of the trunk, alters its direction 
a little and passes with a slightly more pronounced 



278 Surface Forms of Buttock 

upward curve over tlie anterior superior spinous pro- 
cess, but if the limb be more fully flexed the fold on the 
front of the thigh tends to curve outwards over the outer 
side of the limb, and the outline of the front of the thigh 
breaks up into two lines, one of which curves downwards 
whilst the other is continued upwards. The angle formed 
by these two lines overlies the prominence of the anterior 
superior iliac spine (see Pis., pp. 252, 274). In the fully 
extended position of the limbs, with the muscles in a 
powerful state of contraction, a well-marked hollow lies 
behind the trochanter major. This is caused by the tight- 
ening of the fascia, due to the contraction of the gluteus 
maximus. In front, this hollow is bounded by a rounded 
elevation which passes from the anterior extremity of the 
iliac crest, downwards and slightly backwards, to the front 
of the trochanter ; this depends upon the presence of the 
fleshy fibres of the tensor fasciae femoris (Pis., pp. 44, 54, 86, 
318, 338). The deepest part of the hollow corresponds to the 
angle formed by the tensor fasciae femoris and the gluteus 
maximus ; it is rounded off above by the surface elevation 
produced by the fleshy part of the gluteus medius, which 
lies superficially in the interval between the tensor and 
the gluteus maximus. When the thigh is flexed this 
hollow appears as a well-marked furrow, the lower part 
of which runs down along the outer side of the limb 
behind the trochanter and upper part of the shaft of the 
thigh-bono, whilst the upper end curves upwards round 
the oud of the trochanter, following the direction of a line 
towards the middle of the iliac crest, midway between 
which and the trochanter it gradually fades away. The 
anterior border of this furrow is the more pronounced, and 
depends on the contraction of the tensor fasciae and the 
anterior filires of the gluteus medius, which together 
form a well-marked elevation on the anterior half of the 
outer .side oi" tho limb : in ibrced contraction of these 



Surface Forms of Bitttcck 279 

muscles their outlines are still further defined by a furrow 
which lies between them (Pis., pp. 44, 104, 252, 274, 382). 

In dealing with these details the student must not over- 
look the fact that great muscular development, and a greater 
or less abundance of subcutaneous fat, modify very much 
the character of the surface forms, a fact which he will 
specially note in connexion with the representation of the 
female figure. In well-selected female models, owing to 
the existence of a thick fatty subcutaneous layer, the influ- 
ence of the muscles and bones on the surface is much 
reduced ; the forms are more rounded, and the depres- 
sions, when they exist, are less sharply defined and much 
shallower than in a male of athletic build. These facts 
are sufficiently emphasized in the plates given for reference 
(Pis., pp. 34, 36, 52, 54, 80, 86, 124, 252, 262 270, 274, 278, 
308, 318, 338, 366, 438). 



CHAPTER X 

THE THIGH 

Before passing to the consideration of the thigh, the 
kuee-joint requires description. The lower end of the 
thigh-bone is expanded and forms two broad recurved pro- 
cesses called the internal and external condyles. Posteriorly 
the ends of these processes, which project backwards behind 
the lower end of the shaft, are separated by a deep notch 
about a finger's breadth in width. When the femur is held 
so that the shaft is vertical, the inner of these processes 
projects beyond the level of the external ; when the con- 
dyles of the femur are placed on some ilat, horizontal 
surface, such as a table, so that both condyles are in contact 
with it at the same time, the shaft of the bone assumes 
an oblique direction as seen from the front or back. If, in 
place of one femur, the two thigh-bones be taken and 
placed side by side iii this way on a table, with their lower 
ends close together, the upper extremities, with the inturned 
heads and nocks, will be separated by a considerable space, 
an interval which corresponds to the pelvic width between 
the two acetabular hollows. This is a fairly accurate way 
of estimating the position of the femur in the thigh, since, 
in the living, the plane of the knee-joint is very nearly 
horizontal, and as the knees should just touch each other in 
the erect position it follows that the line of the thigh-bone 
very nearly corresponds to that displayed in the above 
experiment. 

The anterior, inferior, and posterior aspects of the con- 
dylfH are smooth, and in the recent condition coated with 
articular cartilage. The. inner surface of the inner condyle 



The Femur 



281 







X5 



nVlttl 



d 



c 



'!\ '111 



B^V'. 



m\\ 



Right thigh-bone (femur). 
Fig. 140. Front view. Fig. 141. Outer side. FiG. 142. Lack view. 



:40 

a. Head. 

h. Trochanter major. 

c. Trochanter minor. 

d. Neck. 

e. External condyle. 



f. Articular surface of condyles. 

g. Inter-condyloid notch. 

li. Surface for attachment of gluteus 

maximus. 
i. Internal condyle. 



282 Bones of the Leg 

is rounded and prominent, and projects froni the line of 
the shaft more than does the outer, the external surface 
of which is somewhat flattened and less prominent. 
Towards the hinder part of the outer surface of the external 
condyle there is a well-marked groove in which the tendon 
of a muscle is lodged. 

The condyles of the thigh-bone are important deter- 
minants of surface form. The size of the knee depends 
upon their development, and to their disposition is also due 
the rounded projecting form of the joint on the inner 
side as compared with the flatter appearance along its 
outer aspect. 

The bones of the leg are two in number; they are 
placed side by side, and so firmly united to each other 
by ligaments that any movement between them is ren- 
dered impossible. They differ very much in size ; the 
inner, called the tibia or shin-hone, is by far the stouter 
and stronger of the two. It alone enters into the forma- 
tion of the knee-joint, and supports the entire weight 
of the trunk and thigh above. The Jibula, which is a long 
slender bone, lies along the outer side of the tibia, to which 
it is immovably united by joints and ligaments. The 
fibula boars no share in the articulation of the knee, but 
along with the tibia enters into the formation of the ankle- 
joint. The fibula is of small service as a means of support, 
but furnishes a bony attachment for many of the muscles 
of the leg. As regards the form of these bones, the tibia 
(or inner bono) displays a shaft with two expanded ex- 
tremities ; the upper end, which supports the condyles of the 
femur, ojjuals thorn in width, and forms two tuberosities, 
an tuuar iind uii outer. The latter more overhangs the 
Hhaf't aii<l is slightly more projecting than the former, 
ii^'th tuUrosities project backwards from the line of 
tiHi Hhaft to a slight extent ; their upper surfaces form 
two soniowhat rounded or oval areas, separated in the 



The Tibia 



283 



middle line b}" a well-marked process called the spine, 
whicti projects upwards and occupies the notch between 




MCT 



aa 



w 



f 



)ii\ 



Fig. 143. Front 
view. 



Right tibia and fibula articulated. 

Fig. 144. Back Fig. 145. Outer Fig. 146. Inner 
view. view. view. 



t. Tibia, inner bone of leg. 

a. Tubercle of tibia, to which ligament 

of patella is attached. 

b. External tuberosity. 

c. Internal tuberosity. 



d. Head of fibula. 

e. External malleolus ^fibula). 
/. Fibula, 

i. Internal malleolus (tibia). 
8 3. Crest or shin. 



the condyles of the femur when that bone is in position ; 



284 The Tibia 

it is upon the upper surfaces of these tuberosities that 
the condyles of the femur rest in the various positions 
of the limb. Whilst the transverse width of the tuberosi- 
ties of the tibia equals that of the condyles of the 
femur it will be noted that the measurement of the 
tuberosities from before backwards is much less than 
the corresponding diameter of the femoral condyles. At 
some little distance below and in front of the tuberosities 
of the tibia the student will notice a projection called 
the iuherde of the tibia. This process is of importance, as 
to it is attached the powerful ligament, the ligamentum 
patellae, which is connected above with the patella or 
knee-pan, the latter a flattened bone of nearly circular form 
which lies in front of the knee-joint. 

The shaft of the tibia is somewhat triangular in section, 
and thus has three margins. Of these the anterior forms 
a prominent sharp border, which can be traced from 
the tubercle of the tibia downwards, with a gentle 
sinuous curve, towards the anterior surface of the pro- 
jection on the inferior extremity of the bone which 
forms the prominence of the inner ankle. This ridge, 
with which every one is familiar under the name of 
the shin, is superficial throughout its entire length, i. e. 
it is merely covered by skin and superficial fascia. The 
surface of the shaft of the bono immediately to the inner 
side of the shin is smooth and rounded from side to side, 
and may be traced from the inner tuberosity above to 
the inner ankle below. It is widest superiorly, narrowest 
towards the middle of the shaft, and expands again slightly 
nr-ur the ankle. Throughout almost its entire extent 
this Hurfaco is covered merely by skin and subcutaneous 
laitcia; it is only above, close to the inner tuberosity of 
tho bono, tliat it is (;ro.ssed and overlain by the tendons 
of cortjiin niusclos which pass down along the inner side 
of tho kuuu. The hinder border of the shaft limits this 



The Fibula 285 

surface posteriorly, and can be traced downwards in front 
of the muscles of the calf, along the inner side of the leg. 
The other surfaces and remaining border of the bone 
are covered and concealed by fleshy muscles, and have no 
direct influence on the surface forms. 

If the under surface of the most projecting part of the 
external tuberosity be examined, a small smooth circular 
surface will be noticed. This is for articulation with 
the upper end of the fibula. 

The lower end of the shaft is expanded and enters 
into the formation of the ankle-joint. From its inner 
side there projects downwards a process called the internal 
malleolus which corresponds to the prominence of the inner 
ankle. The further consideration of this part of the bone 
is reserved until the ankle-joint is described. 

Little need be said regarding the fibula or splint-hone. 
It is about the same length as the tibia, but is placed at 
a somewhat lower level in the leg, so that its upper end 
does not reach as high, whilst its lower extremity projects 
beyond the tibia ; the shaft of the bone is extremely 
slender : its thickness is not usually greater than that 
of the little finger. The form and curvature of the shaft 
are liable to very great individual variation, but as this 
part of the bone is surrounded on all sides by fleshy 
muscles, except at its lower end, it matters little what its 
precise shape may be, as it has little direct influence on the 
surface forms. The fibula lies along the outer side of the 
shin-bone, but the direction of the axis of its shaft is not 
parallel to that of the tibia ; in the upper part of the leg 
it lies somewhat behind the tibia, whilst, below, its inferior 
extremity is placed directly to the outer side of the ex- 
panded end of the shin-bone. The ends of the bone are 
enlarged, the upper is the head, the lower the external 
malleolus, a process which forms the prominence of the 
outer ankle. 



286 The Fibula 

The head of the fibula is an irregular rounded process 
of bone, from which passes a short upward projection 
called the styloid process, to the front of which the strong 
external lateral ligament of the knee-joint is attached. 
On the inner surface of the expanded head is a small, 
smooth, circular surface, adapted for articulation with the 
corresponding area already described on the under sur- 
face of the overhanging external tuberosity of the tibia. 
This joint permits of no perceptible movement, the bones 
being firmly united by surrounding ligaments. Situated 
as this articulation is, below the level of the knee-joint, 
it follows that the upper end of the fibula does not, 
share in the formation of that joint and is in no wise 
concerned in supporting the condyles of the femur. The 
student will do well to determine in his own person the 
precise position of the head of the fibula. If he follows 
the direction of the outer hamstring, when the knee is 
bent, this will lead him to the head of the fibula, which 
he will recognize as a rounded knob of bone lying just 
below the level of and behind the knee-joint on the outer 
side. This warning is necessary, as most students, when 
asked to place the finger on the head of the fibula, make 
the mistake of pointing to a spot in advance of that 
really occupied by the bone. This part of the bone 
is subcutaneous on its outer and anterior aspect, where it 
is uncovered by muscle ; superiorly it has attached to 
It the external lateral ligament of the knee-joint, whilst 
the outer hamstring, viz. the tendon of the biceps muscle 
of the thigh, passes down to be inserted into it. The 
lower part of the shaft and the inferior extremity of 
tho bono will be further referred to in connexion with the 
dcsfTiption of the leg and ankle. 

Tho knep-joint is the largest joint in the body. By its 
RToat size it aflV)rds adequate support for the weight of 
tho trunk which is transmitted through it. Three bones 



The Patella 2.?i-i 

enter into its formation, the femur, the tibia, and a bone 
not hitherto described, called the patella. When we 
straighten the knee, and no longer contract the muscles 
of the front of the thigh, this last may be felt as a 
movable disk lying in the loose tissues in front of the 
joint. If, however, we contract the muscles of the front 
of the thigh or bend the knee, the patella can no longer 
be freely moved, but is felt lying in close contact with 
the lower end of the thigh-bone, and practically fixed in 
position. 

The patella consists of a disk of bone the anterior 
surface of which is rounded from side to side and slightly 
from above downwards ; the deep surface of the bone is 
adapted for articulation with the condyles of the femur, 
on which it glides as on a pulley. The margin of the 
disk varies in thickness ; inferiorly it is somewhat pointed, 
and has connected with it a strong ligament, called the 
ligament of the patella, by means of which the bone is 
connected inferiorly with the tubercle of the tibia. The 
patellar ligament consists of a thick broad band of non- 
elastic fibrous tissue, so that, whatever the position of the 
limb may be, if the ligament is drawn tight by the contrac- 
tion of the muscles which are attached to the patella, the 
distance between the lowest point of that bone and 
the tubercle of the tibia never varies. In the extended 
position of the joint, when the muscles are in action, 
the lower border of the patella lies about one inch above 
the articular surface of the tibia ; when the muscles are 
relaxed the bone slips to a somewhat lower level, and, 
the strain being taken off, the patellar ligament becomes 
lax. The reader may demonstrate these facts for himself 
by standing erect and alternately contracting and relaxing 
the muscles of the thigh, when the knee-pan will be seen 
to move accordingly. The upper border of the bone is 
thick, and here, as well as at the sides, are attached the 



288 



The Knee-joint 



powerful fleshy muscles which form the extensor group 
of the front of the thigh. 

Tlie patella plays an important part in the modelling 
of the anterior aspect of the knee. Applied as it is to the 
lower end of the femur, it masks the form of the condyles 

in front, and fills up the 
shallow groove which sepa- 
rates them anteriorly and in- 
feriorly, so that, even when 
the joint is fiexed, it gives 
a rounded appearance to the 
front of the knee. 

The knee-joint is exceed- 
ingly complicated in the 
arrangement of its articular 
surfaces and the ligaments 
which strengthen it. It is 
not necessary for present pur- 
poses to enter into a detailed 
account of this articulation, 
except to mention that the 
condyles of the femur, as they 
rest on the upper surface of 
the tuberosities of the tibia, 
are supported bypads of carti- 
lage of a semilunar form, 
which are placed in relation 
to the circumference of each 
rounded facet on the articular 
surface of the tibia. Passing 
from tho sidfs of tho doop notch, which separates the 
fomoral (•oiulyjos posteriorly, to the surface of the tibia 
in front of and Ix^liiiid the spine, are two powerful liga- 
monts wliiclj iroiri their crossed arrangement are called 
tho crncud lujuwcuis. On cither side, the articulation is 




Kkj. 147. Tlio bones of the ex- 
tondfd ripht knee, front view. 

/. Kf>nmr. 
fi. Fihulft. 
tilt. Til.ia. 
f. Kxtcrniil ronri yin of fpmnr. 
i. InU-riifil roiidylo of foniur. 
h. H«-ft.| f.f fihiila. 
J'. I'iit<.llii, or kneo-pan. 
/. liiRiiniont of the pjitolla. 
t. Tul>orcle of tiliia. 



The Knee-joint 



289 



strengthened by strong lateral ligaments \ the internal 
stretches from the inner surface of the internal condyle 
of the femur down over the inner tuberosity of the tibia, 
and is attached to the shaft of the bone just below that 
process. The external lateral ligament, which is of a 




Fig. 148. The bones of the ex- 
tended right knee, outer side. 

/. Femur. 
ji. Fibula. 
tib. Tibia. 
e. External condyle of femur. 
h. Head of fibula. 
■p. Patella, or knee-pan. 
I. Ligament of the patella. 
t. Tubercle of tibia. 



Fig. 149. The bones of the ex- 
tended right knee, inner side, 

f. Femur. 
fi. Filmla. 
tib. Tibia. 

i. Internal condyle of femur. 

li. Head of fibula. 

jj. Patella, or knee-pan. 

I. Ligament of the patella. 

t. Tubercle of tibia. 



rounded cord-like form, is connected above with the outer 
surface of the external condyle of the femur, and is attached 
below to the head of the fibula. 

The capsule posteriorly is formed by a broad mem- 
braneous band, called the posterior ligament, which is 
united above to the femur along the upper edge of the 



u 



290 



The Knee-joint 



notch between the condyles, and is attached below to the 
posterior margin of the upper extremity of the tibia. 

In front, the joint is enclosed by a thin capsule with 
which the ligament of the patella is incorporated, whilst 
additional support is afforded by tendinous expansions 
from the muscles, which are inserted into the sides of the 
patella. 

A glance at the bones will enable the reader to understand 
that there is one part of the articular surface of the femoral 
condyles which never comes into contact with the tibia or 





KifJ. 150. Tho l,onoa of tlie bent 
right knee, outer side. 

a. Fomiir. 

h. Tibia. 

f- Fibula. 

e. External condyle of femur. 



Fig. 15 t. The bonos of the bent 
right knee, front view. 

i. Internal condyle of femur. 

J?. Piitella. 

I. Ligament of the patella. 

t. Tubercle of tibia. 



Semilunar cartilages, for if the bones be placed one on the 
top of tho other, as in the extended position of the limb, 
a considerablo articular surface is displayed on the front of 
the condyles, wlii.Ji lies above the level of the tibia. It is 
on tins that tho patella rests in extension. When the joint 
w bont tho femoral condyles hinge and roll on the upper 
Hurfaco of tho tibia and on the semilunar cartilaginous pads 
iiforo-doscribcd in such a manner that in extreme flexion 



Movements of Knee-joint '2()i 

their hinder surfaces rest on the upper surface of the tibia, 
whilst the surfaces of the condyles, which were previously 
in contact with the tibia in the extended position, are 
now turned forwards ; they are thus brought into contact 
with the deep surface of the patella, which cannot shift 
its position, owing to its connexion with the tubercle of the 
tibia by the patellar ligament. Thus, whilst in extension 
the patella rests on a part of the femoral condyles peculiar 
to itself, it passes, in flexion, to rest on portions of the 
condylar articular surfaces, which were previously in contact 
with the tibia and semilunar pads. 

The chief movements of the knee are those of flexion 
and extension. Flexion is limited by the back of the calf 
coming into contact with the back of the thigh. Extension is 
checked, when the leg is brought in line with the thigh, by 
the action of certain ligaments. In this extended or straight 
position of the knee it may be said that all the ligaments 
of the joint are in a state of tension, except one of the 
crucial ligaments and the part of the capsule in front of 
the joint, the principal ligament of which, the ligamentum 
patellae, may or may not be tense according to the state of 
contraction of the muscles on the front of the thigh. By 
this means the joint is mechanically locked, so that little or 
no muscular effort is necessary to enable us to stand erect 
with the knees straight. The explanation of this is that 
under these conditions the line of gravity falls in front of 
the axis of rotation of the joint, and this force keeps the 
ligaments tense, thereby mechanically locking the joint and 
preventing any further movement of extension (Fig. 131). 
The reader may convince himself of this in one or other of 
two ways. If, when standing erect, he sways the body 
backwards, so that the line of gravity falls behind the axis 
of the joint, he will only be able to prevent himself from 
falling by the exercise of very violent muscular effort, and 
he will realize that the muscles of the front of the thigh 

u 2 



292 locking of the Knee-joint 

are thrown into a state of powerful contraction ; but if tlie 
body be again swayed forward, so as to bring into action 
the ligaments aforementioned, no muscular effort is neces- 
sary to maintain the joint in its extended position, and the 
fleshy mass on the front of the thigh may now be felt soft 
and relaxed. Or again, an admirable demonstration of the 
mechanical principles involved is afforded by the schoolboy 
trick of knocking the knees from under one. The victim, 
unconscious at the time of any such attack upon his 
stability, is standing upright with his muscles in a state 
of relaxation when the blow is struck behind the knee. 
The joint is then held in the extended position by the 
tension of the ligaments only ; the force of the blow, 
however, knocks the knee suddenly forwards, and thus 
causes the line of gravity to fall behind the axis of the 
joint, with the usual result, that, before the subject of 
the experiment has time to recover himself by bringing 
into play the powerful muscles which control the joint, he 
falls to the ground. 

The degree of extension of the joint depends, like that 
of the hip, on the length of its ligaments. Under ordinary 
conditions these are sufficiently long to permit of the leg 
and thigh being brought into the same straight line ; ex- 
ceptionally, when these ligaments are longer, the joint may 
ho morn fully extended, so that the front of the leg forms 
with the front of the thigh an open angle, with a corre- 
sfK^nding curve along the back of the limb. As Briicke has 
pointed out, this is more or less characteristic of the type 
so commonly represented in the period of the German 
ronaiH.sance, and, though minor degrees of this condition are 
tolcTJihle, it should bo discarded when unduly emphasized 
in tho male, or when present in the female. 

Nv hen the knee is straight we have no power of rotating 
the logon the thigh; if wo wish to turn the point of the 
to«*8 inwards or outwards wo do so by rotating the whole 



Muscles of Thigh 293 

limb, the movement taking place at the hip-joint. When 
the knee is bent, however, any one, who tries it, may satisfy 
himself that a limited amount of rotation of the leg on the 
thigh is possible,, as the ligaments of the joint are relaxed. 
The range of this movement is not great, and is checked by 
the tightening of the ligaments of the knee. 

In considering the arrangement of the fleshy muscles 
which form the bulk of the thigh it is necessary to study 
several groups, two of which, viz. , that in front of and that 
behind the shaft of the thigh-bone, are immediately con- 
cerned in the movements of the knee-joint. The third 
group, that which lies along the inner side of the thigh, is 
mainly associated with the movements of the thigh at the 
hip, and particularly with that action, called adduction, 
whereby the outspread limbs are brought together. It is 
therefore called the adductor group of muscles. 

x^.11 the muscles of the thigh are encased in a sheath of 
fascia, which invests the limb like a tight-fitting stocking. 
We have already seen how this sheath is thickened aloug 
the outer aspect of the thigh to form the strong ilio-tibial 
band, which is connected above with the insertions of the 
gluteus maxim us and tensor fasciae femoris muscles, and 
is attached below to the external tuberosity of the tibia 
{ante, p. 275). The fascial sheath is subdivided into three 
compartments by means of fibrous partitions, which pass 
from its deep surface to become attached to the thigh- 
bone. The compartments thus formed are for the lodge- 
ment of the groups of muscles just mentioned ; that in 
front contains the extensor group, that behind the flexor 
muscles, whilst the internal compartment is occupied by 
the adductors. 

The muscles of the extensor group, or those which lie 
along the front of the thigh, are four in number, viz. 
the crureus, on either side of which are the vasti, named 
internal and external according to their position, whilst, 



294 



Extensor Muscles of Thigh 



superficial to all, is the rectus femoris. All these muscles 
are inserted into the patella, and are oftentimes referred 
to as the quadriceps extensor, on account of the four-headed 
arrangement of their fleshy mass. For present purposes 
it will be most convenient to describe the muscle as con- 
sisting of two parts, a superficial and a deep ; the latter 
includes the crureus with the vastly one on either side 
of it. It is unnecessary to consider the details of the 
attachment of the several parts of this fleshy mass; it 
is sufiicient to point out that it clothes the front and 
sides of the thigh-bone, extending as high as the base 
of the outer side of the great trochanter, and following 
inwards and downwards from that point the spiral 
line which sweeps across the upper part of the thigh- 
bone, from the root of the great trochanter externally to 
the linea aspera or rough ridge which passes along the 
posterior aspect of the shaft of the bone. Inferiorly these 
muscles are inserted into the sides and upper border of the 
patella. The arrangement of the fleshy fibres is such that 
t he whole length of the outer side of the shaft of the thigh- 
Ixme, n^aching as far back as the linea aspera, is covered 
witli a tlnck fleshy layer which imparts to the outer side 
of* the tliigli its rounded contour and flowing outline, whilst 
internally the shaft is clothed by the vastus internus, which 
sweeps round the inner side of the bone to the rough 
ndge on its posterior aspect. This part of the muscle 
attains its greatest thickness in the lowest quarter of 
the thigh, where its rounded surface not only imparts 
a fullness to the iroiit of the thigh in this situation, 
but also influences the outline of the inner side of 
tlio Innl), where it is overlain by a strap-like muscle 
called the mrtorius^ wliicli here passes down along its 
inner side (Fig. i^o). 

TluTo JH a characteristic difl'erence in the way in which 
the lutf.ral porljcns of tins Heshy mass are connected with 



The Vasti 



295 



the patella. Tiie outer part, or vastus externus, passes down 
to be attached to the outer side of the upper border of the 
patella, from which it sends a general expansion over the 
anterior part of the capsule of the knee. The vastus internus, 
on the other hand, reaches a much lower level on the inner 
side of the thigh, and is insert-ed into the upper half of the 
inner border of the patella. The 
lowest fibres of the vastus internus 
are very oblique in their direction, 
and overlie the upper part of the 
internal condyle of the thigh- 
bone, whereas those of the external 
vastus are much more vertical in 
their direction and in the erect 
position do not cover the outer side 
of the external condyle at all, but 
pass down to the patella above it ; 
here the posterior border of this 



Fig. 152. Front view of the muscles of 
the right thi<jli. 

a. Tensor fasciae femoi u. 

h. Vastus externus. 

c. Rectus femoiis. 

d. Vastus internus. 

e. Sartorius. 

f. Psoas and iliacus. 

g. Pectineus. 

h. Adductor longtis. 

i. Gracilis. 

j. Patella. 

k. Tubercle of tibia with ligamentum patellae 

atrache<l. 
I. Ilio-tibial band, 
m. Head of fibula. 
n. Subcutaneous surface of tibia. 
0. External oblique. 
p. Aponeurosis of external oblique. 
q. Placed over sheath of rectus, 
r. Gluteus medius. 
a. Anterior superior iliac spine. 
t. Iliac crest. 

«. Inner head of gastrocnemius. 
V Tibialis antirus. 




oq6 Rectus Femoris 

part of the muscle is defined by a tendinous edge which is 
emphasized during contraction. Behind this a few fleshy 
fibres of the crureus become superficial, but as they are 
overlain by the lower part of the ilio-tibial band they do 
not exercise much influence as determinants of surface form 
(Fig. 152, and Pis., pp. 54, 72, 86, 216, 318, 328, 338, 382). 

Resting on this deeper stratum of muscle, and occupying 
a position corresponding to a line leading from the anterior 
superior iliac spine to the patella, there is a superficial 
muscle called the rectus femoris. This muscle has a fusi- 
form belly, with 'upper and lower tendons of attachment. 
It arises by two tendons, the details of which need not 
be described, from the iliac part of the haunch-bone, just 
above the acetabulum or cup for the reception of the head 
of the thigh-bone. At this point the muscle lies deeply, 
having to its outer side the tensor fasciae femoris, whilst 
in front of and along its inner side for a short distance is 
tlie above-mentioned sartorius^ a muscle to be presently 
described. The fleshy belly of the rectus crops up in the 
angle formed by these two muscles, and passes downwards 
towards the patella, into the upper border of which it 
is inserted by a broad flat tendon about three inches 
in leiigtli. As the fleshy belly overlies the deeper stratum, 
it only partially covers it, so that the vasti appear on 
either side of it. The fleshy part of the muscle imparts 
a fullness to the front of the thigh which is not only 
due to the development of its fibres and the thickness 
of the subjacent muscular stratum, but is also dependent 
on the forward curve of the shaft of the thigh-bone, to 
which rofbrenco has been already made (p. 255 ; Pis., pp. 54, 
72, 86, 216, 274, 318, 338, 366, 382). 

The above muscles act as powerful extensors of the knee — 
that is to say, they straighten the leg. This takes place in 
one or otlior of two ways. Suppose wo are seated on a 
clmir with tho knees bent at a right angle, we can straighten 



Sartorius 297 

the legs in one or other of two ways, either by raising the 
feet from the ground, in which action the upper is the fixed 
attachment of the muscle ; or by rising from the chair and 
standing on our feet, in which case the leg and foot are the 
fixed points, and it is the thighs which move, carrying with 
them the trunk. These different actions of the extensor 
muscles are of common occurrence, and depend, as has been 
said, on which is the fixed end of the limb, the thigh or foot ; 
but, as has been already noticed (p. 291), their action is not 
necessary to enable us to stand erect, for in this position, 
when the foot is resting on the ground, the patella may 
be felt lying loose in front of the knee. It becomes 
fixed, however, if these muscles be contracted, or if the 
extended limb be raised from the ground. The reader 
will have noticed a difference in the origin of these 
various parts of the quadriceps extensor. The ^ deeper 
stratum arises from the thigh-bone, whilst the superficial 
part or rectus arises from the haunch-bone ; the latter 
therefore crosses the front of the hip-joint and may also 
act as a flexor of that joint (Fig. 152). 

There is a muscle which occupies a position in front of the 
upper part of the thigh, and which subsequently runs down 
along the inner side of the limb ; this is the sartorius^ already 
alluded to. It cannot be grouped with either the extensor 
muscles above described or with the adductor mass which 
lies along the inner side of the thigh-bone, but may now be 
conveniently studied, as it forms a sort of natural boundary 
between these two groups. The muscle, which is of elongated 
form, in fact the longest in the body, takes origin above 
from the anterior superior iliac spine (anterior extremity 
of the iliac crest) and from the bone immediately below it ; 
it passes obliquely across the front of the upper part 
of the thigh so as to reach its inner side about the 
middle, and, coursing down along this aspect of the limb, 
it passes behind the most prominent part of the internal 



298 



Sar tortus 



condyle of the thigh-bone and along the inner side of 
the knee. Below this point it forms a thin expanded 
tendon, which turns forward beneath the level of the 
inner tuberosity of the tibia and is inserted into the 
subcutaneous surface of the upper part of the shaft of 
that bone, close to the tubercle in front. The muscle 
resembles a strap which has been twisted round the 
front of the limb in a spiral fashion. It thus helps to 
divide the front of the thigh into two regions: an 
outer and lower, occupied by the extensor muscles which 
have just been described, and an upper and inner, which 
contains the adductor group. The sartorius overlies the 
rectus femoris at its origin, as well as the hinder portion 
of the vastus internus along the lower and inner aspect 
of the thigh. It also lies in front of the insertions of the 
adductors (Fig. 152; Pis., pp. 72, 86, 216, 318, 366, 382). 

The action of this muscle is to flex the knee and hip- 
joints : when the knee is bent it acts as an internal 
rotator of the leg on the thigh; it also assists in evert- 
ing the entire limb. The relation of the muscle is best 
understood by a reference to the Plates, pp. 274, 318. 
It will be noticed that its influence on the surface forms 
is not great. It helps to define the upper limit of the 
lUllncss of the vastus internus and rectus from the hollow 
of the thigh which lies above the sartorius and between 
it and the furrow of the groin. In violent action, when 
the thigli is flexed upon the trunk, the superior attach- 
ment of the muscle to the anterior superior iliac spine 
may innn ;iu outstanding ridge on the surface of the 
limb (PI., j). 216). In many models the angular interval 
U'twcon tlMi origins of the sartorius in front, and the 
t<-n.sor fa.s(riae i'emoris to the outer side, is represented on 
the Hurfaco l.y a furrow or dimple. It is here that the 
n-ctus femoris, concealed at its origin, becomes superficial 
(PIh, pp. 58, i.jO, 158, 298). 



Adductor Muscles 299 

Owing to the oblique position of the thigh-bone, there 
is a triangular interval between the inner side of the 
shaft of the bone, the inner border of the limb, and th^ 
pelvis above. This interval is occupied by the adductor 
muscles. They form a fleshy mass of triangular shape, 
attached above to that part of the pelvis in front of the 
acetabulum which is formed by the pubis, and that por- 
tion of the ischium which lies in front of the ischial 
tuberosity. Externally and inferiorly these muscles 
pass to be inserted into nearly the whole length of 
the back of the shaft of the thigh-bone, reaching as 
low as a prominent spur on the upper surface of the 
internal condyle, whilst internally they assist in forming 
the outline of the inner side of the thigh. This fleshy 
mass is broken up into several muscles, named the ad- 
ductor longus, adductor brevis, adductor magnus, pectineus^ 
and gracilis, but it is unnecessary to enter into a detailed 
account of them all, as they influence the surface forms 
rather by their bulk than by their details. As has been 
already stated, they lie above and to the inner side of 
the sartorius muscle : here, as they stretch across from 
the front of the pelvis to the upper part of the thigh- 
bone, they assist in forming the floor of the depression 
which lies immediately below the groin, and which is 
called the hollow of the thigh. This corresponds to a 
triangular interval between the sartorius on the outer 
side and the inner border of the adductor longus on the 
inner side. The base of the triangle, which is directed 
upwards, corresponds to Poupart's ligament. The floor of 
this space is deepest in the centre, and corresponds on the 
inner side to the anterior surfaces of the pectineus and 
adductor longus, whilst' externally two muscles, called 
the psoas and iliacuSj which pass down from within 
the pelvis, under cover of Poupart's ligament, ibrm the 
outer half of the floor of the space. The influence of 



ooo The Gracilis 

these structures on the surface form is very much modified 
by the presence of an abundance of fat and other tissues. 
and depends also on the position of the limb. It 
is here that the large blood-vessels and nerves which 
enter the thigh are placed, and, lying as they do in 
a considerable quantity of fat, they serve to mask and 
obscure the outlines of the structures above enumerated ; 
the hollow as such only exists, in a well- nourished model, 
when the thigh is flexed upon the trunk (Pis., pp. 38, 274). 
In this position the boundaries of the space become more 
distinct, and the surface contours flattened, whereas when 
the thigh is fully extended the front of the limb assumes 
a fullness which is largely dependent on the fact that 
the head and neck of the thigh-bone, which underlie 
some of the structures enumerated, are thrust forward 
and so cause a bulging of the tissues which overlie 
them (Pis., pp. 72, 148, 152, 216). 

Of the adductor group the most important as a determinant 
of surface form is the gracilis. This muscle arises by a 
thin tendon about 2 or 2 J inches broad from the bone, 
close to and parallel with the symphysis pubis. The attach- 
ment extends somewhat behind this joint. It differs 
Iroin the other members of the group in not being attached 
to the thigh-bone. Its fleshy fibres, which form a broad 
strap-like muscle, pass vertically downwards along the 
inner side of the limb, thus coinciding with the outline 
of the upper and inner aspect of the thigh when viewed 
from the. front. A little below the level of the middle of 
the tiiigh it comes in contact with the posterior border 
of the sartorius, which has crossed over the front of the 
thigh to reach the inner side, and here the gracilis usually 
becomeM tendinous. Its tendon is closely applied to the 
l>OHt«rior border of the sartorius, and passes down in 
company with it along the inner side of the knee. Below 
tho internal tuberosity of the tibia the tendon curves 



Action of Adductors 



301 



forwards, and. is inserted under cover of the expansion of 
the sartorius into the inner aspect of the upper part of the 
shaft of the tibia (Pis., pp. 216, 252, 274, 318, 338, 382). 

As their names imply, these muscles ad duct the thigh ; in 
other words, they enable us to draw togei^her the outspread 
limbs. They are usually well developed in those who 
indulge in much riding exercise, 
though of course the reader must 
bear in mind that this remark 
applies only to those who ride 
cross-saddle. Individual members 
of the group are associated with 
other actions ; thus the pectineus 
and adductors longus and brevis 
assist in flexing the thigh, whilst 
the gracilis helps to bend the knee 
and at the same time causes inward 
rotation of the bent leg. The ad- 
ductors as a whole may also assist 



Fig. 



a. 
h. 
c. 
d. 
0. 
f. 
fi- 
ll . 
i i. 

J- 
k. 
I. 

VI. 

n. 

o n. 

pp. 

7- 



153. View of the muscles of the 
back of the right thigh. 

Tensor fasciae femoris. 

Gluteus medius. 

Gluteiis maximus. 

Ilio-tibial band. 

Trochanter major of femur (tbigli-bone). 

Vastus extern us. 

Biceps of thi^h. 

Semitendinosus. 

Semimembranosus. * 

Gracilis. 

Adductor magnus. 

Sartorius. 

Popliteal space or ham. 

Head of fibula (outer bene of log). 

Outer head of gastrocnemius. 

Inner head of gastrocnemius. 

Extornal oblique muscle of abdominal 

■wall. 
Origin of latissimus dorsi. 
Posterior superior iliac spine. 
Posterior layer of lumbar aponeurosis. 




302 Flexor Muscles of Thigh 

in turning the limb outwards by reason of their insertion 
into the back of the shaft of the thigh-bone. 

The hamstring muscles form the flexor group, which 
is placed on the back of the thigh. They consist of the 
biceps of the thigh, the semitendinosus, and the semimem- 
branosus. They all take origin from the tuberosity of 
the ischium (lower and hinder part of the haunch-bone), 
and pass to be inserted into the bones of the leg: two 
into the tibia or inner bone, one into the fibula or 
outer bone. They thus connect the bones of the leg 
with the pelvis, and, as they cross over the back of the hip 
and knee-joints, they therefore control the movements of 
these two articulations. 

This flexor mass forms a thick fleshy column which 
occupies the middle of the back of the thigh. It is not 
sufficiently wide to influence either the inner or outer 
outline of the limb when viewed from behind, for external 
to it the fleshy fibres of the vastus externus, overlain 
by the ilio-tibial band, are the determinant of the surface 
outline, whilst on its inner side the adductor group, 
covered by the sartorius below and the gracilis above, 
corresponds to the outline of the inner aspect of the thigh. 
In the erect position the origin of these flexor muscles 
from ihe tuberosity of the ischium is concealed by the 
lowor })ord»'r of the gluteus maximus. When the thigh 
is floxf'd on the trunk, however, the lower border of the 
«hitf!U.s maximus slips forward over the ischial tuberosity, 
thf;roby more fully exposing the superior attachment of 
those muscles (Fig. 153 ; Pis , pp. 44, 52, 54, 252, 274, 318)- 

The biceps and semitendinosus lie side by side and 
superficial to the semimembranosus ; the line of separation 
botweon ihc biceps and semitendinosus corresponds to 
the mi'idlo line of the back of the thigh. At a point 
correspond in^r pretty closely with the junction of the 
lower with tho middle third of the thiirh these two 



Hamstring Muscles 303 

muscles separate from one another. The outer one, or 
biceps, passes towards the outer side of the knee, below 
which it is inserted into the head of the fibula,, whilst 
the semitendinosus is directed downwards towards the 
inner side of the knee, and is inserted into the inner 
iaspect of the upper part of the shaft of the tibia, just 
b3low the inner tuberosity of that bone and under cover 
of the tendinous expansion of the sartorius. The biceps 
differs from the other members of this group in possess- 
ing a second head of origin from the thigh-bone, hence 
its name. This femoral origin is called its short head, 
in contradistinction to the long head, which arises along 
with the other hamstrings from the ischial tuberosity. 
The short head of the biceps arises from the rough line 
on the back of the thigh-bone, below the bony insertion 
of the fibres of the gluteus maximus, extending down to 
near the external condyle (Pis., pp. 52, 54, 274, 318, 338, 366). 

There is a marked difference between the forms of 
the biceps and semitendinosus. The latter ends in a long 
and slender tendon (to which circumstance it owes its 
name), about the level at which the two muscles sepa- 
rate from one another, viz. at the junction of the lower 
with the middle third of the thigh, whereas the biceps 
remains fleshy until it has reached the level of the knee 
(Pis., pp. 252, 318, 338, 366). 

The, semimembranosus, ^0 cdlX^di on account of the peculiar 
arrangement of its tendinous parts, lies at its origin 
under cover of the preceding muscles. The bulk of the 
fleshy part of the muscle is placed on the inner side of 
the middle line of the back of the thigh. In this situa- 
tion the fleshy belly of the semitendinosus rests upon it 
above, whilst, below, the tendon of that muscle may be 
traced downwards on the surface of the fleshy part of 
the semimembranosus, which reaches as low as the upper 
border of the internal condyle of the thigh-bone. Inter- 



004 Hamstring. Tendons 

nally the semimembranosus is in relation above to a 
portion of the adductor magnus, whilst in the lower two- 
thirds of the thigh it lies close to the hinder border of the 
fleshy belly and tendon of the gracilis muscle. Curving 
round the hinder end of the internal condyle of the 
thigh-bone, the muscle passes to be inserted by a strong 
tendon into the back of the inner tuberosity of the 
tibia (Pis., pp. 52, 252, 274, 318, 338, 366). 

It is to the presence of these muscles that the roundness 
of the back of the thigh is due. We have already seen 
that they exert no influence on the outer and inner outlines 
of the limb, but if the thigh be viewed from the side they 
determine its shape as we trace it from the fold of the 
l)uttock to the back of the knee, the surface outline being 
due to the fleshy bellies of the biceps and semitendinosus, 
though the semimembranosus not unfrequently has a direct 
influence on the surface form a little above and behind the 
knee. The reader may, however, better satisfy himself as 
to these details by a reference to the Plates, pp. 54, 252, 
274' 318, 338, 366). 

It is particularly in the region of the ham or the 
hollow behind the knee that these muscles are most 
rojulily distinguished. When the knee is bent their 
rounded cord-like tendons may be felt with ease on 
liotli the inner and outer aspects of the hinder surface 
of the joint. These tendons are hence called the ham- 
wtrings, a term which is also applied to the muscles 
with which they are connected. The outer hamstring^ 
or tfiidon (,{' th^ biceps, can be readily traced to its 
insertion into the jioad of the fibula, whilst the inner 
haniHtriufjs, of which the more superficial is the tendon 
of tho semitrMidinosus, can also be easily recognized. 
rhrtt of tlio scmitendinosus passes to the inner side of the 
'Jpp^T iMid of thf. slijift of the tibia, whilst the tendon of 
tho s'-iniiiioiiil,ranosus can bo traced with more difficulty 



Action of the Hamstring Muscles 305 

to the back of the internal tuberosity of the tibia (Pis., 
pp. 252, 274, 318, 328, 338, 366). 

As regards the action of these muscles, the student must 
bear in mind the fact already referred to, viz. that they 
pass over both the hip and the knee-joints ; but note 
that in the case of the hip the muscles lie in relation 
to its extensor aspect, whilst in the case of the knee they 
are placed in relation to its flexor surface. They may 
thus act as extensors of the hip as well as flexors of the 
knee. They combine with their flexor action on the knee 
a certain power of rotating the bent leg. The biceps helps 
to rotate the leg outwards, whilst the semimembranosus 
and semitendinosus will counteract this by turning the 
leg inwards at the knee. 

Their action as extensors of the hip may best be under- 
stood by reference to a very simple experiment. When 
we endeavour to touch the toes without bending the knees 
a great strain is put on the hamstring muscles ; they are 
stretched to their full extent, and our ability to perform this 
feat depends on the extent to which they have been 
exercised in this particular way. It is when we recover 
ourselves and again assume the erect position by straight- 
ening the trunk on the limbs at the hip-joints that we 
bring into play the extensor action of these muscles. As 
has been stated, the extent to which we can bend forward 
without flexing the knees depends on the length of these 
muscles. This controlling action of the hamstrings is illus- 
trated in another way ; we can only raise the limb, or in 
other words bend the thigh, to a limited extent, barely to 
a right angle with the trunk, when the knee is extended, 
but if on the other hand the knee be flexed the tension on 
the hamstrings is at once relieved, and the thigh can be 
bent to such a degree that we can bring its anterior surface 
in contact with the front of the trunk. Similarly there is 
no difficulty in touching the toes if we slightly bend the 



THOMSON 



3o6 Action of the Hamstring Muscles 

knees. The accompanying diagrams serve to illustrate 
these facts (Figs. 154. 155). 

The form of the thigh tapers from the hip to the knee. 
Its roundness depends largely on the quantity of fat present 
beneath the skin. In a muscular model but sparingly covered 
with fat the grouping of the muscles into an internal and 
upper group (adductors), an external and lower group (ex- 
tensors), and a posterior group (flexors) is at once apparent, as 
these several re<2ions resolve themselves into surfaces which 





Fia. 154. Fig. 155. 

Biaf^rams to illustrate how flexion at tlie hip-joint is controlled by the 
hamstring muscles. In Fig. 154 the hamstrings are represented tightly 
Ktretched when the knee is straight. In Fig. 155 the muscles are shown 
n-liixfMl when the knee is bent. A greater amount of flexion is thereby 
permitted at the hip-joint. 

are more or less distinctly defined from one another— the 
two former by the furrow corresporiding to the sartorius, 
the two latter by the furrow which pass?s down the outer 
8k1o of thq thigh and corresponds to the posterior border 
of the vastus externus. The fullness on the inner* side of 
tlio thigh passes insensibly into the roundness caused by the 
hamstring group (Pis., pp. 52, 54. 72, 86, 216, 318, 366, 382). 
In the iemalo the separation of the thigh into regions, 
corre.sponding to the grouping of the muscles, is obliterated 
to a very groat extent by the presence of a thick sub- 



Form of Female Thigh 



307 



cutaneous fatfcy layer (Pis., pp. 52, 54, 72, 80, 86, 216. 252, 
262, 268, 270. 278, 298, 308, 318, 338, 366, 434, 438). 

Owing to the greater pelvic width in woman, and the 
consequent greater obliquity of the thigh-bone, the limb 
is relatively wider above compared with its length than 
in the male : this conveys the impression that in the 
female the thigh is shorter than it really is. As a fact, 
the thigh is relatively somewhat shorter than in the male, 





Fig. 156. 



Fig. 157. 



Diagrams showing the greater degree of obliquity of the thigh-bones 
dependent on the greater pelvic width in woman, Fig. 156, as compared 
with man, Fig. 157. 



but in well-proportioned females the shortness is more 
apparent than real, and is dependent on the causes afore- 
mentioned. It may be noted, however, as a matter of 
experience, that it is by no means easy to obtain female 
models with the requisite limb proportions, for in no respect 
do they vary so much. 

The greater breadth of the uppor part of the thigh 
and the greater obliquity of the thigh-bone give rise in 

X 2 



oo8 Hip -width 

women to a knock-kneed appearance. This is further em- 
phasized by the outline of the outer side of the thigh 
forming a more pronounced angle with the outline of the 
outer side of the leg than in. the male (Pis., pp. 2 16,298). When 
from great width of the upper segment of the limb this ap- 
pearance is unduly pronounced it gives rise to an unpleasant 
impression, and models which display this feature should 
be discarded, though much may be done to remedy these 
unpleasant lines by placing the limbs in such a position 
as to modify considerably the appearance of this defect. 
The condition above referred to, when not unduly em- 
pliasized, is a characteristic feature of the female figure, 
and imparts to it a sense of refinement and modesty in 
harmony with the whole sentiment of the figure. In women 
there is a tendency to the massing of fat on the outer side 
of the thigh below the level of the trochanter. This, as 
has been already explained (p. 271), causes the width of this 
part of the figure to fall lower than in the male, in whom 
it is generally situated on a level with the trochanters, 
but in cases where this fat is present in too great quantity 
it destroys the symmetry of the thigh and produces an 
unpleasant outline along the upper and outer aspect of 
t lift limb. This difference in the form of the limb in the 
two sexes may best be observed if we view the figure from 
bohmd. In women the greatest width across the thighs 
is seen to lie as a rule on a level with the folds of the 
buttocks, whereas in the male the greatest width is con- 
siderably above this level. These differences are apparent 
in the plates, pp. 34, 52, no, 142, 216, 434). 

The outlines of the thigh, when viewed from front or 
back, dfti)on(l on iho vastus externus on the outer side, and 
on the gracilis above and the sartorius below, on the inner 
Hide. Tho student should remember that the ilio-tibial 
band ov.Tlifts the fleshy fibres of the vastus externus, and 
when tight leads to a compression of the muscle, thus 



Contours of Thigh 309 

giving rise to a flattening of the form along the outer 
side of the limb. This is best seen when the model stands 
on one leg, or when the weight of the trunk is mainly 
supported on one leg, with the knee extended, whilst the 
other leg is bent and slightly advanced (PL. p. 298). In this 
position the bent leg carries little weight, but merely acts 
as a support to steady the limb upon which the bulk of 
the weight rests. In profile the outline of the front 
of the thigh depends upon the sartorius, rectus femoris, and 
the vastus externus. If the limb be slightly rotated out- 
wards, a small part of the vastus internus, as it crosses 
over the internal condyle of the thigh-bone, comes into 
direct relation with the outline just above the knee. In 
this view of the limb, the surface outline, due to the fleshy 
bellies of the vastus externus and rectus, is frequently 
interrupted towards its lower part by a shallow hollow, 
corresponding to the position of an arching band of fibres 
which cross the general investing fascia of the limb ; these 
fibres are connected with the ilio-tibial band behind, and 
curve downwards and forwards over the front of the 
thigh on the upper part of the lower third of the limb. 
Richer ^ calls them the arched hand of the fascia of the 
thigh (Pis., pp. 72, 86, 366). 

Posteriorly the outline depends on the hamstrings, the 
biceps, or semitendinosus chiefly, whilst, below, the semi- 
membranosus directly influences the surface contours for 
a short distance above the kn'ee (Pis., pp. 54, 80, 86, 252, 274, 
318, 338, 366). 

When the limbs are straight with the knee^ together 
there should be but a slight interval between the thighs, 
and that only where the sartorius muscles curve back to 
lie along the inner side of the limb. In women the thighs 
may be in contact all the way down. This difterence 
is due to the greater quantity of subcutaneous fat, and 
' Anatomie Arttstique, Paul Richer. Paris, 1890. 



310 Straightness of Limb 

when an interval exists between the limbs in this position 
it should be much less than in the male. In either sex 
the space between the thighs when the knees are in 
contact should never be carried up as high as the fork, 
as such a condition is indicative of a meagre develop- 
ment of the lower limbs and produces a most unpleasant 
impression. (Pis., pp. 216, 268.) 

In men of athletic build one not unfrequently meets 
with a certain amount of outward curve in the limbs. This 
bow-legged appearance, in minor degrees, is quite con- 
sistent with a normal growth and an athletic development, 
and must not be confused with those cases in which the 
curves of the limb are the result of disease. Briicke ^ has 
laid down a rule which enables the student to determine 
when this outward curve of the limb has exceeded the limits 
consistent with a well-shaped leg. He takes two straight 
lines, the inner from the middle line of the trunk at the level 
of the pubis, the outer from the outer side of the thigh, just 
where the trochanter lies beneath the surface. Both lines 
are carried down so as to meet at a point corresponding 
to the most elevated part of the instep of the foot. As these 
two lines cross the front of the knee, the patella should lie 
between them ; in cases where the patella lies outside these 
limits the curve of the limb is unduly great, and the form 
inelofrant. It follows from this that, in men in whom 
this form of limb is met with, the inner sides of the knee 
may not bo in contact when they stand erect with the heels 
togother, but may be separated by an interval the width 
of which is limited by the rule already referred to. Such 
a condition is inconsistent with the form characteristic of 
tho female, and models displaying such a tendency should 
bfi avoided. 

Tho variations in the form of the thigh, due to alterations 

• TUf Human Fhjure, I'rolossor EnioHt Brucke. London : Grevai & Co., 
I891. ' 



Form of Knee 



311 



in its position, are best understood by a reference to the 
plates, pp. 274, 318. In flexion of tbe thigh on the trunk 
it is always well to recognize the position of the anterior 
superior spine of the iliac crest, as this gives us the key 
to the drawing of the tensor fasciae femoris, a muscle 
which exercises an important influence on the surface 
forms of the upper and outer part of the limb. In slight 
degrees of flexion the fold of the groin is deepened, and the 
outer limit of that furrow corresponds to the bony point 
in question. When flexion is carried farther, the line 
of flexion which crosses the front of the upper part of 
the thigh, just below the furrow of the groin, becomes 





Fig. 158. 



Fia. 159. 



emphasized, and these two folds as they reach the outer 
side of the limb form a V o^ Y"Shaped fold between 
the sides of which the anterior superior iliac spine can 
be distinctly felt. This is well shown in the plates, pp. 
80, 104, 124, 252, 274, 318. 

The consideration of the surface forms of the knee is 
extremely difficult. In the first instance it is very im- 
portant that the student should have an accurate knowledge 
of the shape of the bones which enter into the formation 
of this joint. The most common defect met with in the 
knee is its size ; this tends as a rule to be too big, 
a circumstance which is principally owing to the large- 



312 



Form of Knee 




Fio. i6o. The right knee with tbe 
muscles relaxed. 




Fig. i6i. Diagram of the right knee 
with the muscles relaxed, showing the 
arrangement of the parts on which the 
surface form depends. 




Pw. .6a Tlio rlRht. kn,... with tho 
niiiiolua contrucicd. 




Fia. 163. Diagram of the right knco 
with the nuisclos contracted, showing 
the Hirangtiment t>f parts. 



Form of Knee 313 

ness of the articular ends of the bones, though the presence 
of a superabundance of fat in this region may assist in 
emphasizing the defect. The joint should be small, though 
not unduly so, as this may tend to impart a weak appear- 
ance to the limb. It should form a summit to the taper 
of the thighs, and link the thigh and leg together in 
such a way as to carry the flow of the lines from one 
portion of the limb to the other without any abrupt 
interruption of their curves. 

Along the inner side of the joint the outline of the thigh, 
determined by the sartorius muscle, should flow evenly and 
continuously over the prominence of the internal condyle 
to the upper part of the shaft of the tibia below. The outer 
side of the joint, less prominent and somewhat flattened, 
corresponds to the bottom of the curve formed by the 
outline of the outer side of the thigh above and the swelling 
of the calf below. In front the form of the patella should 
be distinct in the male, though in the female it may be less 
noticeable. It should be small and not unduly prominent, 
else the knee may have a pointed appearance, which is 
objectionable (Pis., pp. 62, 72, 216, 328, 434). 

The patella is connected above with the muscles of the 
front of the thigh, and below, by means of its ligament, 
with the tubercle of the tibia ; these details are not recog- 
nizable when the muscles are relaxed, but are plainly seen 
in action. In repose the patella drops to a slightly lower level 
and lies loosely in the tissues in front of the joint, being 
supported below by two considerable pads of fat, which 
occupy the intervals between the ligament of the patella 
and the front of the joint on either side. By the contrac- 
tion of the muscles of the front of the thigh the patella is 
drawn up so that its lower border lies about an inch above 
the level of the articular surface of the tibia. The ligament 
which connects it with the tubercle of the tibia is thus 
put on the stretch, and becomes conspicuous as a surface 



314 Fo7^m of Knee 

elevation, which is usually marked off above by a shallow 
furrow corresponding to its line of attachment with the 
patella. On either side the fullness of the ligament is 
maintained by the pads of fat already mentioned, which 
help to soften its outline. Superiorly a flattened tri- 
angular depression, leading up into a furrow, corresponds 
to the tendinous insertion of the muscles into the upper 
border of the knee-pan. The fullness on either side of 
this depression corresponds, on the inner side, to the fleshy 
fibres of the vastus internus, which curve obliquely across 
the internal condyle of the thigh-bone to reach the upper 
half of the inner border of the knee-pan, whilst at a 
higher level the fibres of the vastus externus, as they sweep 
down to be inserted by tendinous fibres into the outer 
part of the superior border of the patella, limit the surface 
depression externally. The arching fibres of E-icher, as they 
pass across the vastus internus, tend to emphasize the 
bulge of the lower part of this muscle (PL, p. 72). These 
details are ordinarily absent in the knee of the female, 
in whom we have a less strong muscular development and 
a greater abundance of subcutaneous fat. In the antique 
there is little suggestion of detail, the forms being kept 
simple and rounded. In females great variety of modelling 
i.s met with, depending on the disposition of the fat ; but 
as a rule the existence of the patella is oftenest indicated 
hy a slight hollowing and flattening of the surface along 
its outer side, thus emphasizing its presence. It is by no 
means uncommon, when the joint is forcibly extended, 
to meet with a triradiate furrow in front of the joint, one 
Innb of the I'urrow overlying the ligament of the patella, 
whilst the two upper limbs serve to define the lower 
and outer borders of the bone itself, the fullness between 
th«'H« lK3ing du(i to the shape of the patella, whilst the 
round.Ml Ibnns on either side of the descending furrow 
ttro causi'd by the disposition of the fat on each side of 



I 



i 



Form of Knee 315 

the ligament (Pis , pp. 72, 216, 298, 434, and Figs. 160 and 
162). 

As viewed from the outer side, the outline of the front 
of the knee is due to the form of the femoral condyles 
and the patella. The position of the latter depends on 
whether the muscles of the front of the thigh are contracted 
or not. It is more prominent when the knee is forcibly 
extended than when it is bent, as in the latter condition 
the patella slips into the groove between the femoral 
condyles. But be it noted that, the ligament of the patella 
having once been put on the stretch, the distance between 
the tubercle of the tibia and the lower border of the patella 
can never vary, whatever be the position of the joint. In 
this view of the limb the relation of the femoral condyles 
to the upper end of the tibia is well seen. They should 
appear as if well supported on the head of the tibia, and 
should not display a forward thrust, as if there was a risk 
of their slipping over the front of the tibia. This appear- 
ance is by no means uncommon in models, and imparts 
to the limb an extremely ugly outline, the line of the front 
of the leg appearing to lie behind the line of the front of 
the thigh, instead of being continuous with it over the 
surface prominences of the knee. In flexion of the joint, 
as the patella sinks into the groove between the two 
condyles, the rounded form of the front of the joint becomes 
more and more due to the condyles, the inner of which, 
being the more prominent of the two, helps to determine 
the outline, even though viewed from the outer side. The 
roundness caused by this condyle is further emphasized by 
the fibres of the vastus intemus, which are curving obliquely 
across it to join the inner border of the patella (Pis., pp. 
54, 80, 86, 216, 252, 262, 270, 274, 318, 338. 366, 438). 

The outer side of the joint is overlain by the ilio-tibial 
band, which is here passing down to be attached to the 
outer tuberosity of the tibia, in front of the head of the fibula. 



Form of Knee 




The bones of the extended knee (right side). 
Fig. 164. Outer side. "^10.^63. Inner side 

/. Femur. fi. Fibula. 



tih. Til<iii 

e. External t^oivlylo of femur. 
Y 1 III. mill condyle of femur. 



h. Head of fibula. 
2). Patella or knee-pan. 
I. Ligament of the patella. 
t. Tubercle of tibia. 





Tlu; bonos of tho l)(>nt knee (right side). 
Fi«;. 166. Kn.iit vi.'w. Fig. 167. Outer side. 

a. Foinur. i. Cnternal condyle of femur. 

p. Patella. 



// Tibia. 

r. Kibulu. 

«. KxUtriiul condylu oi fnnur. 



l. fiigament of the patella. 
t. Tuber<!lo of tibia. 



Form of Knee 317 

In such actions as put a strain on this band it forms a sur- 
face relief distinct from that caused by the vastus externus. 
which lies in front. Behind the ilio-tibial band the tendon 
of the biceps muscle may be traced to the head of the 
fibula ; in passing down, it causes a surface elevation 
corresponding to its form and direction. In flexion this 
relief is at once emphasized. The relations of the other 
structures in different positions of the joint are best 
understood by a reference to the plates, pp. 252, 275, 318,338. 
The roundness of the inner side of the knee is due to the 
projection of the internal condyle and the internal tuberosity 
of the tibia. The lowest fibres of the vastus internus partly 
overlie the former, whilst curving down over the posterior 
half of the inner side of the joint are the fibres of the 
sartofius (here fleshy), behind which there lie in the fol- 
lowing order, from before backwards, the tendons of the 
gracilis, semimembranosus, and semitendinosus. The semi- 
membranosus tendon passes away from the surface opposite 
the level of the internal tuberosity of the tibia, into the 
posterior border of which it is inserted. The tendons of all 
the other muscles here enumerated pass down to be attached 
to the upper part of the inner surface of the shaft of the 
tibia below the internal tuberosity, the sartorius forming 
a broad expansion underneath which the other two tendons 
are united to the bone, that of the gracilis lying on 
a higher level than that of the semitendinosus. These 
details are not indicated on the surface forms by separate 
reliefs ; together they combine to form a rounded elevation 
which curves over the inner side of the joint. In flexion 
the two inner hamstrings, viz. the tendons of the semi- 
membranosus and semitendinosus, become very prominent, 
particularly the latter, and serve to carry the line of the 
back of the thigh across the inner and posterior aspect of 
the flexed joint. On either side the spring of the muscles 
of the calf, from the back and upper parts of the femoral 



3i8 



Rectus fcmoris. 
Band of Richer. 
Sartorius.^ ^' 

Reel fern. tend, 
I 'list. intern.'^ 
Pate/h.-~.. 
Fat...,^ 

I nt. condyle. - ' 
Ligpat.. '■' 
Sar tortus.'' 
Semitendin. 

Tibid, subcut 
surface. _ 

Castrocnem . 
Solcus. - 

I Uxor longus 
di<^itorum pedis. 

I cndo A chillis.^ 

Internal mall. 
Tibialis post. 

Tibialis ant. 







•-7 

31 » 
31 
32 
33 

M 
35 
36 
37 



(jaitrocnemius. 
.Sulcus. 

Tibialis anticus. 
Peroneui longus. 

Ten do A chillis. 
Long extensor of great toe. 
Pcroneus brevis. 
Long extensor of toes. 
Peroneus tertius. 
Lxternal malleolus. 
/: xt brev digttorum 
Os (aids 



1 Rectus abdominis, 

2 External oblique. 

3 Erector spinae. 

4 Iliac crest. 

5 Atit.sup. iliac spine. 

6 Tensor fasciae femoris. 

7 Gluteits medius. 

8 Sartorius. 

9 Trochanter major. 

10 Gracilis. 

11 Scnii-me7nbra?tosus. 

12 Gluteus maxi7nus. 

13 Adductor rnagnus. 

14 Semi-tendinosus. 

1 5 r Rectus femoris. 

1 6 Ilio-tibial band. 

17 Vastus externus. 

18 Band of Richer. 

1 9 Biceps cruris, long head. 

20 Biceps cruris, short head. 

21 Patella. 

22 Fat. 

23 Jlio-tibial band. 

24 I /cad of fibula. 

25 Lig. patellae. 




m-^ 



Form of Knee 319 

condyles, imparts a fullness to the back of the limb, behind 
ani below the joint (Pis., pp. 252, 274. 318, 338, 366). 

The consideration of the surface forms on the back of the 
knee must be postponed until the muscles of the calf have 
been described. (See p. 342.) 



CHAPTER XI 



THE LEG AND FOOT 



The muscles of the leg ^ are concerned in the movements 
of the foot and toes. Before considering them, something 
must therefore be said about the bones of the foot and the 
ankle-joint. 

The bones of the leg have been already described in the 
previous chapter, but a more detailed account' of their 
lower extremities is necessary before the reader can fully 
appreciate the structure and movements of the ankle-joint. 
Unlike the knee, both bones of the leg enter into the forma- 
tion of the ankle, though the tihio, or inner bone plays 
a much more important part in its construction than the 
Jihula or outer bone. 

The lower end of the tibia is expanded, and on its inferior 
surface displays a quadrilateral articular area, hollow from 
before backwards and very slightly convex from side to 
side. On the inner side of this the bone is prolonged 
downwards to form a broad and more or less pointed process 
called the iniernal malleolus. The inner aspect of this 
process is subcutaneous, and corresponds to the surface pro- 
jection of the inner ankle. The outer surface of the internal 
malleolus is provided with an articular facet, which is con- 
tinuous with that already described on the under surface 
of the expanded lower end of the tibia. 

Th*^ low(;r .■11(1 (A' iho jihula is also enlarged, and forms 
a prfKu-sH called <!,,. external malleolus. This is narrower 

' The tern. \r^ jh l„..,e iii-pll.td to tluit niirt of the limb which lies 
below the knoc. 



Bones of Leg 



321 



and more pointed than the internal malleolus. The outer 
surface of the external malleolus is subcutaneous and forms 

d ^^ C r b b 



aa 



Fig. 168. Front 
view. 




/ 



1 



e 



Plight tibia and fibula articulated. 

Fig. 169. Back Fig. 170. Outer Fig. 171. Inner 



view. 



view. 



view. 



t. Tibia, inner bone of leg. 

a. Tubercle of tibia, to which ligament 

of patella is attached. 
6. External tuberosity. 
c. Internal tuberosity. 



d. Head of fibula. 

e. External malleolus (fibula). 
/. Fibula. 

i. Internal malleolus (tibia). 
s a. Crest or shin. 



the elevation of the outer ankle. The inner side of the 
lower end of the fibula is firmly united to the outer side 



THOMSON 



222 The Ankle 

of the inferior extremity of the tibia, beyond which it 
projects considerably, and is smooth and covered with arti- 
cular cartilage. When the two bones are joined together 
the two cartilage-covered surfaces become continuous, 
and an articular recess is formed, bounded on either side 
by the inner and outer surfaces respectively of the two 
malleoli, and between by the under surface of the lower 
end of the shaft of the tibia. The student should now 
study the relations of the malleolar processes. The internal 
malleolus is broader from before backwards, less pointed, 
lies at a higher level, and is placed some- 
what in front of the external, which is more 
prominent and pointed, placed lower, and 
lies on a plane behind that of the internal. 
These are all details of the greatest impor- 
tance in the drawing of the foot, and the 
student would do well to impress them on 
his memory. The anterior margins of the 
Fig. 172. Sketch ^^^ malleoli are rounded off in front, but 
of bones of right posteriorly their borders are grooved for 
ankle as seen from ivii in i-ii i'i 

behind the lodgement ot certain tendons which 

pass down behind them and so help to 
soften the surface contours corresponding to these more or 
less abrupt edges. One of the bones of the foot fits into the 
recess between the two malleoli. The joint between these 
three bones is called the anlde-joint. 

Just as we have carpal, metacarpal, and phalangeal bones 
in the hand, so wo have tarsal, metatarsal^ and phalangeal 
l)0ne8 in the foot. The tarsal bones correspond in the foot 
to the carpal or wrist-bones of the hand. They are seven 
in number, in place of eight as in the carpus : this is due to 
the fact that the representative in the foot, of the pisiform 
bone of the hand, has become fused to another of the tarsal 
bones, thus leading to a reduction in the number of these 
bones by one. 




Bones of the Foot 



323 



The tarsal bones form a striking contrast to tlie bones of 
the wrist ; they are much larger and stouter, and constitute 
a far larger proportion of the foot 
than do the corresponding bones of 
the hand. If the length of the inner 
border of the foot be taken from 
the heel to the tip of the great toe, 
the skeleton of the hinder half of the 
foot is made up of these tarsal bones, 
the half in front being formed of 
the metatarsals and greatly reduced 
phalanges or toe-hones. The advan- 
tage of this arrangement is at once 
obvious. It is on the feet that we 
habitually stand and rest the weight 
of the body, and for this purpose 
strength and solidity are necessary. 
The foot is not a prehensile organ like 
the hand, in which great freedom of 
movement is obviously an advantage. 

The tarsal bones, of which a dia- 
gram is here given (Fig. 173), are 
named the astragalus^ os calcis, navi- 
cular, internal, middle and external 
cuneijorms, and the cuboid. 

Of these the two most important 
are the astragalus or hucJcle-hone and 
the OS calcis or heel-hone ; the rest 
help to form the rounded surface on 
the back of the foot called the instep. 




Fig. 173. The bones of 
the right foot as seen 
from above. The tibia 
and fibula have been re- 
moved so as to expose 

\ 



a. Astragalus 

b. Os calcis or heel- 

bone 

c. Navicular or sca- 

phoid 

d. Cuboid /-Tarsus. 
6. External cunei- 
form 

/. Middle cuneiform 
Q. Internal cunei- 



The astragalus consists of a hinder ,. ,. ^ /rMetatarsus. 



3 33 3 3- Phalanges 
bones. 



or toe- 



or larger part, the body, the upper 

side of which is provided with a 

saddle-shaped articular surface. The fore part of the bone 

is called the head. This rounded surface, which is moulded 

Y 2 



324 



The Astramlus and Os calcis 



on an ill-defined neck, articulates with the navicular bone, 
and thus supports the skeleton of the inner border of the foot. 

The hinder part of the bone is of little importance as 
a determinant of surface form, but is noteworthy because it 
links together the bones of the foot with the bones of the leg. 
Superiorly it fits into the recess between the two malleoli, 
which thus prevent its lateral displacement and also check 
excessive movement from side to side. Inferiorly it rests 
on the upper surface of the heel-bone, whilst in front it 
articulates, as has been said, with the navicular. 

The OS calcis or heel-hone is not placed directly beneath 
the astragalus, but lies under the outer half or so of that 
bone. It supports the astragalus in part on its upper surface, 
and in part by means of a bracket-like process called the 
sustentaculum tali^ talus being another name applied to 
the astragalus. The inner side of the os calcis forms a wide 
hollow which is overhung by the sustentaculum. The broad 
groove which lies behind the inner ankle, and between it 
and the prominence of the heel, allows the passage of the 
numerous structures (tendons, vessels, &c.) which run from 
the back of the leg downwards into the sole of the foot. 
Tiie most marked feature of the os calcis is its large pos- 
UinoT extremity, which forms the prominence of the heel 
Tlio length of this process varies in different individuals; 
it is more prominent in a thin, narrow, and long foot than 
in a sliort and broad foot. The powerful tendon of the 
musflos of the calf, called the tendo Achillis, is inserted 
into this process. The outer side of the os calcis is sub- 
cutaneous except where crossed by two tendons which pass 
down behind the external malleolus: these tendons help 
to carry the relief of the external malleolus on to the 
Hurfttco form corresponding to the outer side of the heol- 
bono. In front the os calcis articulates with the cuboid, 
and thus supports the bones which lie along the outer 
border of the loot. 



The Ankle-joint 325 

Such further description of the remaining tarsal bones 
as may be necessary is for the present delayed until the foot 
as a whole is considered. 

The aiikle- joint is the articulation between the tibia and 
fibula above, and the astragalus below. The fibula shares but 
little in the transmission of the weight through the leg to 
the foot ; by its external malleolar process, however, it affords 
support to the outer side of the joint, and thus prevents 
lateral displacement of the astragalus. It is through the 
under surface of the lower extremity of the shaft of the 
tibia, which rests on the saddle-shaped surface of the upper 
aspect of the astragalus, that the bulk of the weight passes. 
The projection of the internal malleolus on the inner side 
assists in strengthening the joint internally. The ankle 
is further supported on either side by very strong lateral 
ligaments which are attached above to the malleolar processes 
and pass downwards as radiating bands which are connected 
with the surfaces of the adjacent bones in front, below, and 
behind. Anteriorly and posteriorly the capsule of the joint 
is completed by thin and weak ligaments. 

The movements of the ankle-joint are mainly those 
of flexion and extension. Under ordinary conditions the 
axis of the foot is placed at right angles to the axis of 
the leg. The term flexion is applied to that movement in 
which the joint is bent so as to bring the back of the foot 
nearer the front of the leg. Extension is the reverse action ; 
in it the axis of the foot is drawn more directly into line 
with the axis of the leg, the heel is raised, and the toes 
are pointed. The reader may easily satisfy himself that in 
the extremes of flexion and extension the degree of lateral 
play of the joint varies very considerably. When the joint 
is strongly flexed the articular surfaces are forced together 
very firmly, owing to the fact that the wider part of the 
upper articular surface of the astragalus is driven home 
between the two malleoli and acts like a wedge, thus 



326 



The Ankle-joint 



ti'^litening the joint. In extension the narrower por- 
tion of the articular surface of the astragalus occupies 
the interval between the two malleoli, the whole joint is 




I'iG. 174. Bones of right foot, outer view. 




i'lu. 175. Ijones of left foot, inner view. 



a. Aitrn:;ahig. 

6. Oi calciii (heol-bono). 

f. N»vjrulur. d. Cuboid. 

t. Kit4Tnnl cunt'ifonn. 

/ Mi<i<lle cuneiforiii. 



</. Internal cuneiform. 

h. External malleolus (fibula). 

an. Metatarsus. 

J. Phalanges. 

k. Internal malleolus (tibia). 



much looser, and a slight amount of lateral play is now 
I)os.siljle. 

TIm, foot may also bo turned so that the sole is directed 
inwurds or outwurd.s as desired, the latter movement only 
to a very jinntod extent. These movements take place at 



Muscles of the Leg 327 

the joints between the tarsal bones and not at the ankle, 
though the slight lateral play of the latter joint may assist 
a little in imparting more freedom to the movement. 

The muscles of the leg are subdivided into three groups : 
those lying in front of the bones, those behind, and those 
which run along the outer side of the fibula. The leg, 
similarly to the thigh, is invested with a sheath of fascia 
like a stocking : along the inner side of the limb this sheath 
is blended with the antero-internal subcutaneous surface 
of the shaft of the tibia, so that it ceases to exist as a 
distinct layer as it lies over the bone. From the deep 
surface of the sheath along the outer side there pass in 
partitions which connect it with the fibula. These inter- 
muscular septa^ as they are called, separate the muscles 
which lie along the outer side of the fibula from those in 
front and behind. In the region of the ankle the fascia 
of the leg becomes thickened and forms more or less 
distinct bands, one of which passes across the front of 
the ankle, another over its inner, and a third over its 
outer side ; these are called annular ligaments, and serve to 
retain in position the numerous tendons which pass over the 
different aspects of the joint, preventing them from being 
drawn away from the surface of the bones in whatever direc- 
tion the foot is moved (Pi's., pp. 216, 252, 318, 328, 338, 366). 

The muscles which lie along the front of the leg are 
the following — the tibialis anticus, the extensor proprius 
hallucis (special extensor of the great toe), the extensor 
longus digitorum (long extensor of the toes), and the peroneus 
tertius. These muscles arise partly from the tibia, partly 
from the fibula, and also from the interosseous membrane 
which connects the two bones throughout nearly their 
whole length, and which, in the interval between the 
two bones, separates the muscle of the front of the leg 
from those which lie deeply on the back. The tendons 
of these four muscles pass down in front of the ankle-joint 



328 



<; (n 






5 ^ 



„>3 ,<3 >> 

0, k. ^ 



5 ^ 





'• •M in 



^ <: o\ Q 



i 

n 



« 5 



i i 



it 



«t '* 



'^ < < 



~ 5 ■fc 



H 
S^ 
O 

(4 
fH 

H 
O 
O 
Ph 

Q 

O 
M 

Hi 

h^ 



Tibialis anticus 329 

under cover of the anterior annular ligament; they are 
therefore flexor muscles of the ankle, though the reader 
will notice that some of them are named extensors. This 
is an illustration of how the action of a muscle varies 
according to the joints over which it passes ; thus the 
extensor muscles of the toes pass along the dorsal or ex- 
tensor surface of the toes, and in action will straighten 
or extend them, but as they pass down to reach the toes they 
cross over the front or flexor aspect of the ankle and thus 
become flexors of that joint. 

Of these muscles the innermost is the tibialis anticus. 
It lies along the outer side of the shaft of the tibia, from 
the upper two-thirds of which it arises, as well as from the 
external tuberosity of the same bone : deeply it takes origin 
from the interosseous membrane. The muscle becomes 
tendinous about the middle of the leg, and, following the 
line of the shin for some distance, passes over the middle 
of the front of the lower end of the tibia, across the ankle- 
ioint beneath the anterior annular ligament, and reaches 
the middle of the inner border of the foot, round which 
it turns to be inserted into the inner and under surface 
of the internal cuneiform bone and the base of the meta- 
tarsal bone of the great toe (Pis., pp.216, 318, 328, 338, 366). 

Above, where the muscle is thick and fleshy, it serves 
to conceal the outline of the sharp anterior border of the 
tibia; it carries the roundness of the innef surface of 
the leg on to the front, imparting a fullness to it, and con- 
cealing the shank-like appearance which is obvious when 
this muscle is wasted. The tibialis anticus is a flexor 
of the ankle, and also assists in raising the inner border of 
the foot from the ground and turning the sole inwards. 

Lying to the outer side of the tibialis anticus is the 
long extensor of the toes. This muscle arises from the 
external tuberosity of the tibia in front of the point of 
its articulation with the head of the fibula, from the head 



330 Long Extensor of the Toes 

of the fibula, from tlie anterior surface of tlie shaft of that 
bone, and from the adjacent surface of the interosseous 
membrane. The bulk of the fibres which arise from the 
front of the shaft of the fibula, viz. those which spring 
from the upper three-quarters, unite in front to form 
a tendon which passes down along the anterior edge of 
the muscle in the lower half of the leg. Under cover 
of the anterior annular ligament this tendon divides into 
four separate slips, which spread out below the level of 
the ligament and pass to the upper or dorsal surface of 
the four outer toes, where they form expansions which are 
inserted into the bases of the second and third phalanges 
of these digits (Pis., pp. 216, 252, 318, 328, 338, 366). 

The fieshy fibres which arise from the lower quarter of 
the anterior surface of the fibula have a different insertion 
from the fibres which arise above. This small slip is called 
the peroiieus tei'tius, and its tendon passes to be inserted into 
the dorsal or upper surface of the base of the metatarsal 
bone of the little toe (Pis., pp. 216, 252, 318, 338, 366). 

The peroneus tertius is of little importance from the 
present point of view, and may for all practical purposes 
bo disregarded. 

The fleshy bellies of the tibialis anticus and the long 
extensor of the toes lie close together in the upper half 
of the leg. At the point where these muscles become 
t^'ndinous thoy separate, and in the interval between 
thcrii anotlier muscle appears ; this is the special extensor 
of the great toe. 

riio H2)ecial extensor of the great toe arises from the 
middle three-fifths of the anterior surface of the shaft of the 
fibula, and also from the adjacent surface of the interosseous 
membrane. At its origin it is in part concealed by the long 
extonjwif of the toes and the anterior tibial muscle, but 
becomes HupoHicial as it occupies the interval between 
the t^mdons of these two muscles. The tendon of the 



Peroneal Muscles 331 

special extensor of the great toe therefore occupies an 
intermediate position between the tendons of the foregoing 
muscles, and, entering a distinct compartment of the 
anterior annular ligament of the ankle-joint, passes along 
the inner and upper aspect of the instep to reach the 
dorsal surface of the great toe, into the base of the terminal 
phalanx of which it is inserted. In front of the ankle this 
tendon lies immediately to the outer side of that of the 
tibialis anticus, but when the latter has passed to the middle 
of the inner border of the foot, that to the great toe becomes 
the most internal of the tendons passing along the upper 
surface of the foot. The special extensor of the great toe 
and the long extensor of the toes, as their names imply, 
serve as straighteners or extensors of the toes, but they 
also act as flexors of the foot on the leg (Pis. pp. 216, 
328, 338). 

Lying to the outer side of the long extensor of the toes 
is the group of muscles which arise from the external 
surface of the shaft of the fibula. This comprises the 
peroneal muscles^ of which there are two ; the longer of 
these muscles is the more superficial and overlies the 
shorter one (Pis., pp. 216, 252, 318, 328, 338, 366). 

The peroneus hrevis arises from the lower two-thirds 
of the external surface of the shaft of the fibula and from 
the intermuscular septa on either side of it. It ends 
in a tendon which winds round the back of the external 
malleolus and is inserted, on the outer side of the foot, 
into the projection at the base of the metatarsal bone 
of the little toe. The jperoneus longus arises from the head 
of the fibula and the upper two-thirds of the external sur- 
face of the shaft ; its fleshy J)art overlies the origin of 
the peroneus brevis, and its tendon courses down over 
the outer surface of the same muscle to reach the back 
of the prominence of the external malleolus, behind and 
beneath which it passes in company with the tendon of 



332 Peroneal Muscles 

the brevis to reach the outer border of the foot. At 

a point just behind the prominent base of the metatarsal 

bone of the little toe the tendon enters a groove on the 

under surface of the cuboid (one of the two tarsal bones 

of the outer border of the foot), and courses deeply across 

the sole of the foot to be inserted into the internal 

cuneiform and base of the metatarsal bone of the great 

toe. The tendon as it crosses the under surface of the foot 

lies deeply, and has no influence whatever on the surface 

forms. These two muscles, as they cover the outer surface 

of the fibula, conceal the form of the shaft of that bone. 

Above, the head of the fibula is readily recognized. Below, 

the external malleolar process and the bone immediately 

above it are subcutaneous, occupying the interval between 

the peronei, which pass behind, and the lowest fibres of the 

long extensor of the toes and the fibres of the peroneus 

tertius, which lie in front. In the upper three-fourths 

of the leg the anterior borders of the peroneus longus and 

brevis are in contact with the posterior border of the long 

extensor of the toes, which lies in front ; behind, the peronei 

run alongside the anterior external border of one of the 

calf muscles, called the soleus, which here takes origin 

from the posterior surface of the head and shaft of the fibula. 

Ill tlif5 lower fourth of the leg these muscles separate from 

one another, the tendons of the peronei passing behind the 

external malleolus, whilst that of the soleus is continued 

down to the prominence of the heel. An interval is thus 

formed, which in the living is filled with fat and bridged 

ov<T by certain layers of fascia ; this corresponds to the 

Hurface hollow between the external malleolus and the 

tfindo AchiUis, or tendon of the calf muscles; the depth 

of this liollow varies according to the quantity of fat 

prcHent. Occasionally duo of the deeper muscles of the 

l«ick of tlw. l,.^r, called the long flexor of the great toe, 

bfcom.,s uucoverod m tjio interval above described, though 



Muscles of the Calf 333 

lying at some considerable distance from the surface ; this 
muscle exercises but a slight influence on the surface forms. 

The tendons of the two peronei as they pass down behind 
the outer ankle lie obliquely across the outer surface 
of the OS calcis or heel-bone : in this position they are 
held down by a ligament, called the external annular 
ligament. By this means the prominence of the outer 
ankle is rendered less abrupt, and the surface contours 
become more rounded. The peroneus longus and brevis act 
as extensors of the foot, i. e. they assist in pointing the toes. 
Along with the peroneus tertius they also raise the outer 
border of the foot and turn the sole outwards : the range 
of this movement is limited. Their principal action is 
to antagonize the muscles which turn the sole of the foot 
inwards ; accordingly, when the foot is inverted they will 
draw the foot back again to its normal position. 

The muscles on the back of the leg which constitute the 
prominence of the calf are subdivided into a superficial and 
a deep group. The latter comprises the long flexors of the 
toes and the tibialis posticus, which are placed so deeply, 
however, that they have little direct influence on the 
modelling of the surface, though by their presence they 
impart a fullness to the limb. The tendons of these muscles 
all pass down into the sole of the foot in a series of grooves, 
which lie behind the prominence of the inner ankle and 
between it and the projection of the heel. It is here that, 
to a slight extent, their fleshy bellies crop up between the 
tendo Achillis and the posterior border of the tibia, as will 
be noticed hereafter (Pis., pp. 252, 318, 328, 338, 366). 

The superficial muscles of the posterior group are the 
soleus and the gastrocnemius. The soleus is the deeper of the 
two. It arises from the back of the head and upper third 
of the shaft of the fibula, and from the back of the shaft of 
the tibia along a line which leads from the surface on the 
external tuberosity, where the head of the fibula articulates, 



334 Muscles of the Calf 

obliquely downwards and inwards, to blend with the posterior 
border of the bone, i. e. that border which limits posteriorly 
the subcutaneous internal surface of the shaft. The muscle 
is attached to this border as low down as the junction of 
the middle with the lower third of the length of the 
tibia. The student will observe that the soleus takes origin 
from the posterior borders of both bones of the leg, from 
the tibia on the inner side, and from the fibula on the outer 
side : the importance of this will be hereafter referred to. 

Between the two bones the muscle arises from a ten- 
dinous arch, which crosses over the deeper structures. The 
fleshy fibres, which are short, are inserted into a broad 
tendon, which gradually narrows as it passes downwards. 
The lateral fibres of origin as they spring from the tibia 
and fibula pass obliquely towards the middle line of the 
muscle. The tendon, which also receives the insertion of 
the gastrocnemius muscle, is called the tendo Achillis, SiJid is 
attached below to the back part of the tuberosity of the 
heel-bone (Pis., pp. 104, 252, 274, 318, 328, 338, 366). 

The gastrocnemius, which rests upon and lies superficial 
to tlio soleus, has no attachment to the bones of the leg. 
It arises by two heads from the back of the lower end of 
the thigh-bones, immediately above the condyles. At its 
origin it is partly tendinous and partly fleshy. The two 
bollios lie side by side behind the knee, with the hamstring 
tondons to their inner and outer sides ; below, where they 
have escaped from the confining influence of these structures, 
the bellies of the gastrocnemius become much enlarged and 
bulge out laterally (Pk, pp. 52, 54, 252, 318, 328, 338, 366). 

The inner head is more prominent than the outer,' and 
Homowhat longer. Both bellies are inserted into the super- 
fifirtl aspect of the tendo Achillis, about the level of the 
middle of the leg, the inner head, as has been said, reaching 
a somewhat lower level than the outer. Above, where the 
two heads of the muscle lie behind the knee and between 



Tendo A chillis 335 

the hamstring tendons, they are separated by a V-shaped 
interval which bounds inferiorly the hollow called the ham. 
Below this the angle of the V is continued downwards as 
a linear depression, which serves to indicate the separation 
of the two halves of the muscle: this may be traced right 
down to the insertion, where it opens out to correspond 
with an. interval overl^'ing the tendon and placed between 
the rounded and somewhat pointed inferior extremities 
of the fleshy bellies. 

As will be seen by a reference to the plates, pp. 52, 72, 
2165 318, 328, the inner belly of the gastrocnemius overlaps 
the upper part of the inner or tibial attachment of the soleus, 
and here determines the outline of the limb as seen from 
either front or back. The outer belly, being narrower, does 
not overlap the outer or fibular attachment of the soleus, 
so that the gastrocnemius plays no part in determining the 
surface outline of the outer side of the leg as viewed from 
the back or front ; here the outline depends on the soleus 
above and the peronei below (Pis., pp. 52, 72, 216, 328). 

The tendo AcTiillis, which is the combined tendon of the 
soleus and gastrocnemius, occupies the lower half of the back 
of the leg. Its size and strength vary with the muscular 
development of the model ; superiorly it may attain a width 
of three inches. At this point it receives the insertions of 
the fleshy bellies of the gastrocnemius: gradually diminishing 
in width as it passes downwards, it receives on either side 
the fleshy fibres of the soleus as they run towards the 
middle line of the calf — from the fibula on the outer side 
and the tibia on the inner side. 

At a point about three or four inches above its lower 
attachment the tendon runs down clear of muscular fibres, 
and, gradually tapering, at a point about an inch above the 
tuberosity of the heel it again expands before it is actually 
inserted into the os calcis. At its narrowest part the tendon 
measures about three-quarters of an inch in width, but this, 



336 Tendo A chillis 

as has been said, largely depends on the muscular develop- 
ment of the model : it is inserted into the middle third 
of the tuberosity of the beel-bone. The upper part of the 
tuberosity is separated from the deep surface of the tendon 
by a little sac called a bursa, containing oily fluid, which 
serves to lubricate the opposed surfaces of th.e bone and 
tendon as they move on one another. Not unfrequently 
the bone below the insertion of the tendon projects some- 
what ; this, when covered by the dense tissue of the heel, 
forms a rounded contour distinct from, and below, the 
insertion of the tendo Achillis, which, is often represented 
in the antique, and is well seen in the outstretched left 
leg of the Fighting Grladiator. This form of beel is by no 
means universal, and the student need not be disappointed 
if ho fails to meet with it in the majority of models he 
examines. 

The gastrocnemius and soleus are powerful extensors of the 
ankle. If the foot be raised from the ground and the toes 
pointed, the foot acts like a lever of the first class ; the ankle 
is the fulcrum, the part of the foot in front of the ankle is 
the long arm of the lever which in this instance repre- 
sents the weight, the part of the foot behind the ankle is 
the short arm to which the force exercised by the muscles is 
applied. It is by the contraction of the same muscles that 
wo are enabled to raise ourselves on tiptoe ; in this posi- 
tion the foot is now converted into a lever of the second 
class, tlio fulcrum being represented by the part of the foot 
in contact with the ground, the weight corresponding to the 
ankle, through which the pressure exercised by the bulk of 
the body is transmitted to the foot, the force, as before, being 
applied to the extremity of the heel. 

Hut the reader will note that the gastrocnemius muscle 
differs from the soleus in not being attached to the bones 
of the log. It arises from the lower end of the thigh-bone. 
It therefore passes behind the knee, and will accordingly 



Action of Muscles of Calf 337 

under certain conditions, act as a flexor of that joint. These 
conditions are the fixation of the ankle-joint by the extensor 
muscles on the front of the leg, and the relaxation of the 
extensor muscles of the knee on the front of the thigh. 

In regard to the development of the muscles of the calf 
a point of some practical importance arises. It has been 
shown how the foot is to be regarded as a lever ; the force 
necessary to effect the same results will vary inversely as the 
length of the lever ; thus a short lever will require the appli- 
cation of a greater force to produce the same result than 
when a long lever is employed. It follows from this that 
the development of the muscles of the calf which supply 
the power will stand in some relation to the foot. Experi- 
ence proves that this is the case. AVe find the most marked 
muscular development of the calf associated with a short 
foot and a short heel, while a long foot and a long heel 
are the usual concomitants of a poorly developed calf. Yet 
it by no means follows that the latter type is less capable 
of performing feats of endurance and fatigue than the 
former ; indeed, an examination of the legs of some of the 
best running men of the day goes far to prove that their 
success does not at all depend on an excess in the bulk 
of the calf, for many of them display, what an uneducated 
spectator might regard as, but a feeble development of these 
muscles. 

During powerful contraction of these muscles, as in the 
act of standing on tiptoe, the fleshy bellies of the gastro- 
cnemius become outstanding elevations, their lower ends 
where they are inserted into the tendo Achillis forming 
abrupt margins of a more or less pointed form. At the 
same tinae the fibres of the soleus which lie uncovered on 
either side of the limb form elongated surface elevations, 
which blend inferiorly with the margins of the tendo 
Achillis, the broad expanded upper surface of which corre- 
sponds to a more or less triangular flattened area, which 



338 




Iliac crest.. -[-^^Jjr ,;( 
Ant. sup. 
iliac spine. - 

Sartorius. 



Rectus /em 



Ilio-tibial. 
band. — 

Vastus ext.-^ 

Biceps cruris, 

long head. . 

Baud of Richer.^ 

DtcrPs 
short head.. . 

Vastus cxfenms 
Semi-yneinbrayi.. 

Rectus femoris.. 
Ext.cond.of femur: - - 

Patclln 
Ilio-tibial band. - 

Ligamcntuvi patellae: 
Ileadof fibula^.- --- 

Tubercle of tibia. .-•- 

Tibialis anticus 

Gastrocnemius. 

Peroneus longus 

Soleus. . - - 
^"g extensor of toes. 

Peroneus brevis. . 
Long extefisor of great toe.^ 
hxternal malleolus 

Annular ligament of ankle. [ 
hx tensor brevis digitorum 



-Erector spinae, tendinous part. 
.Gluteus medius. 
. . Posterior superior iliac spine 

;^^a,^ Tensor fasciae femoris . 

^/^. .- Trochanter major. 

. . Gluteus maximus. 
,Semi-tendinosus . 
^Adductor magnus. 
.Semi-meinbranosus. 

_ . .Gracilis. 

.... -Sartorius. 
, . - -Vastus internus. 

■Band of Richer.^ 

. Rectus femoris. 

...-Patella. 

Int. condyle of femur. 

Sartorius. 
■ Semi-tendinosus . 
Lig. patellae. 

Gastrocnemius. 
.jTibia, subcut 
surface. 

. . . Soleus. 

Tibialis 
/ p osticus 

Tendo 
A chillis. 



^Internal 
ann. ligament. 



Surface Contours of Leg 339 

gradually narrows and merges inferiorly with the ridge 
which leads below to the prominence of the heel, and which 
corresponds to that part of the tendon which is free from 
muscular fibres (Pis., pp. 268, 274, 328). 

In the profile view of the back of the limb the outline of 
the upper half or so of the leg depends on the form of the 
fleshy bellies of the gastrocnemius, and will vary according 
to their state of contraction ; below, the outline depends on 
the tendo Achillis. This outline is gently curved — convex 
backwards above and slightly hollow below, where it passes 
to the heel : the latter curve should not be unduly empha- 
sized, as it leads to an unpleasant projection of the heel 
(Pis., pp. 252, 274, 318, 338, 366). 

In front and on the outer side of the limb the anterior 
border of the soleus is defined by a straight linear de- 
pression, which passes from the back of the head of the 
fibula to the outer border of the tendo Achillis ; this line 
serves to separate the calf muscles behind from the peronei 
(long and short) in front (Pis., pp. 274, 338). 

On the inner side of the limb the muscles of the calf 
are very clearly mapped out by the posterior border of the 
tibia. This border, the reader will remember, corresponds to 
that margin of the bone which defines posteriorly the sub- 
cutaneous surface of the shaft, the surface which lies between 
the flexors of the ankle in front and the extensor muscles 
posteriorly. Behind the upper fourth or so of this margin 
lies the inner prominent head of the gastrocnemius, where 
it escapes from under cover of the inner hamstrings as they 
pass to the inner tuberosity of the tibia. The middle third 
of this margin lies in front of the fibres of the soleus which 
arise from the tibia, and which are passing obliquely down- 
wards and backwards to be inserted into the inner border 
of the tendo Achillis. Below that point the posterior border 
of the tibia is separated from the tendo Achillis by an 
elongated triangular interval, the apex of which is directed 

z 2 



340 Surface Contours of Leg 

upwards. It is here that the fleshy bellies of some of the 
deeper muscles, particularly the long flexor of the toes, 
become superficial and exercise a direct influence on the 
surface, helping to fill up the gap that would otherwise 
exist between the tibia and the tendo Achillis (Pls.^ pp. 
252,274,318,338,366). 

The hollow behind the inner ankle is of crescentic form. 
Its greatest width is between the internal malleolus and 
the prominence of the heel ; superiorly it fades away on 
the surface corresponding to the triangular interval above 
refen'ed to ; whilst inferiorly it curves behind and below 
the inner ankle to pass under the inner border of the foot 
and thus reach the hollow of the sole. The margins of this 
hollow are less abrupt than might be expected from an 
inspection of the skeleton ; this is due to the arrangement of 
the fascia, which here forms the internal annular ligament 
and serves to bridge over the interval. It is beneath this 
structure that the tendons of the deep muscles of the back of 
the leg pass to the sole of the foot. The muscles which spring 
from the under surface of the heel-bone, and which run 
along the inner border of the sole of the foot, have also a 
considerable influence in modifying the surface forms ; and 
the distribution of the subcutaneous tissue which here forms 
the pad of the heel should not be overlooked. 

In studying the outline of the leg, as seen from the front, 
the student's attention must be directed to the fact that the 
ontlinos of the inner and outer side of the limb do not 
depond on any of the structures which lie on the front of 
tho log, but are chiefly due to the projection on either side 
of the niusclos of the calf Along the outer side the fibular 
attachment of the soleus determines the outline of about the 
upper tliird of the limb ; below, the outline is carried down 
to the external ankle by the two peroneal muscles (long 
and Hhort). H iho outline of the inner side of the leg be 
divided into thirds, tho upper third is due to the projection 



The Back of the Knee 341 

of the inner belly of the gastrocnemins, the middle third 
to the fibres of the soleus arising from the tibia, whilst the 
lower third, which includes the projection of the inner 
ankle below, depends for its fullness above on the fleshy 
fibres of the long flexor of the toes, which here become 
superficial between the tibia in front and the tendo Achillis 
behind (Pis., pp. 216, 328). 

The hollow behind the knee, the liam, so called, was not 
described in the last chapter^ because the reader was not 
then familiar with all the structures necessary to enable him 
fully to understand the relations of this space. 

The hollow corresponds to a diamond-shaped intermus- 
cular space which lies behind the knee-joint. Above, it is 
formed by the separation of the hamstring muscles as they 
pass outward and inward on either side of the knee, the 
biceps to the outer side, the semitendinosus and semimem- 
branosus to the inner side. Below, the space corresponds to 
the V'Shaped interval between the heads of the gastro- 
cnemius as they arise from the back and upper surface of each 
femoral condyle. The interval is occupied by a large quantity 
of soft fat in which lie the vessels and nerves passing down 
to the leg. Stretching across from the sides of the space is 
a layer of fascia, which is particularly strong in this region ; 
it is really only a specialized part of the general fascial 
investment of the limb which overlies the hollow, imme- 
diately beneath the skin and superficial fat, and serves to 
retain the contents of the space in position. The tenseness 
of this fascia varies with the position of the Irmb : when the 
knee is bent it becomes relaxed, as any one may satisfy 
himself by feeling the back of the knee when the joint 
is flexed. The sharp skin-folds on either side depend 
on the position of the inner and outer hamstrings, within 
which the two heads of the gastrocnemius may be felt 
passing from the back of the condyles of the thigh-bone 
(Pis., pp. 52, 268, 328). 



342 The Back of the Knee 

With tlie limb in the extended condition the fascia is 
rendered tense, and the student will experience difficulty in 
recoo-nizino- the afore-mentioned details unless he is familiar 
with the anatomy of this region. In this position the 
hamstring tendons are best recognized further up the back 
of the limb ; in place of there being a hollow between 
them, there is a distinct fullness over the* back of the 
joint, due to the contents of the space being pushed up 
ao-ainst the tightly stretched fascia, as well as the femoral 
condyles, which, together with the heads of the gastro- 
cnemius, are now forced back as far as possible. The 
positions of the hamstring tendons on either side of this 
central elevation are now indicated by shallow longi- 
tudinal furrows, which pass down towards the inner and 
outer tuberosity of the tibia, the external reaching the 
head of the fibula. In women the inner of these furrows 
is often especially well marked. The appearance may 
perhaps be better described by saying that in the extended 
position of the limb the surface elevation overlying the calf 
is prolonged upwards on the back of the thigh, occupying 
like a wedge the A-shaped interval between the outer and 
inner hamstrings, the positions of which are indicated by 
the shallow furrows above described. Crossing this eleva- 
tion at a level corresponding to the joint is a cutaneous 
fold or lino of flexure. This fold is either slightly curved 
with the convexity directed upwards, or it may display 
a slight obliquity, being a little higher on the outer than on 
the inner side. Its depth varies considerably in different 
individuals: in a spare model it is but faintly marked, 
but in one in whom there is much superficial fat, or in 
women, it is readily recognized. The fold is of course 
Htretchod during extension of the joint, but becomes at 
once emphasized wIk^u the knee is bent (Pis., pp. 52, 54, 252, 
268.270,308,318). 

Little need bo said beyond what has been already stated 



Form of Leg in Female 343 

in regard to the influence of the structures already described 
on the form of the limb ; in powerful contraction the 
lines of separation of the muscles on the front of the leg 
are indicated by a series of shallow longitudinal furrows 
all more or less parallel, and best seen in the upper or 
fleshy part of the leg. Passing from within outwards, 
we can recognize the furrows separating the anterior 
tibial muscle from the long extensor of the toes, the long 
extensor of the toes from the peronei (long and short), and 
the peronei (long and short) from the fibular origin of the 
soleus. The surface markings on the back and inner side 
of the leg have been sufficiently explained (Pis., pp. 54, 72, 
86, 216, 252, 318, 328, 338, 366). 

We have taken as our type the spare athletic male. The 
influence of the muscles on the surface forms is much 
reduced whenever the subcutaneous fat becomes abundant : 
this is exemplified in the female, in whom the limb presents 
a imiformly smooth appearance with little or no indication 
of subjacent structures except under the most exceptional 
circumstances ; the outlines are more flowing, and the curves 
more uniform. In this connexion it may be noted that 
in the female the fullness of the calf descends to a lower 
level than in the male. In women, owing to their more 
delicately modelled bones, the surface forms of the inner 
and outer ankle are less prominent and more rounded than 
in the male. The shortness of the female foot is no doubt asso- 
ciated with the greater relative development of the muscles 
of the calf (Pis., pp. 52, 72, 80, 216, 252, 268, 274, 308, 338). 

As has been already stated in the earlier part of this 
chapter, the skeleton of the foot consists of tarsal, metatarsal, 
and phalangeal bones. The part of the foot formed by the 
tarsal bones exceeds in length that formed by the metatarsal, 
and similarly that formed by the series of metatarsals 
exceeds in length that formed by the phalanges or bones 
of the toes. This arrangement of the bones of the foot is in 



;44 



Bones of the Foot 



striking contrast with what one sees in the hand ; the 
combined length of the phalanges or finger-bones is greater 

than the length of the palm or meta- 
carpal bones, and these in turn exceed 
the length of the part of the hand 
formed by the wrist or carpal bones. 
It is obvious that these differences are 
correlated with the functions the foot 
is called upon to discharge, for the 
toes, which correspond to the most 
freely movable part of the hand — the 
fingers — are much reduced in their 
relative proportions, whilst that part 
which corresponds to the supporting 
part of the hand, the wrist, is greatly 
increased. As has been already 
pointed out, this increase in the size 
of the tarsal elements imparts greater 
strength and solidity to the foot, 
requirements of which it stands much 
in need from the nature of the duties 
it has to perform. 

The astragalus and os calcis have 
been sufficiently described (ante^ p. 
323). The astragalus supports the 
inner column of the foot, which con- 
sists, in order from behind forwards, 
of the navicular^ the three cmiei- 
forms, and the three metatarsal hones 
which support the three inner toes. 

The OS calcis, or heel-bone, supports 

the skeleton of the outer column of 

the foot, which includes from behind 

forwards the cuhoid and the metatarsal bones of the two 

outer toes. The outer border of the foot, as we proceed from 




Fig. 176. The bones of 
the right foot as seen 
from above. The tibia 
and iibula have been re- 
moved !-o as to expose 



a. Agtrajfftlus 

b. Oi calcis or Leol- 

c. Nuvir ular or sca- 

phoid 

d. fulmij 
t. Kxtflmal cunei- 
form 

/ Middloruneiforir. 
g. InUmal cuuci- 

forni 
iiHL Mfttatargus. 
iiiii I'iialari(;o« 01 

bon«i«. 



\ 



Tarsus. 



toe- 



Bones of the Foot 345 

tlie heel forward, is formed by the os ealcis or heel-bone, the 
cuboid, the metatarsal bone, and the phalanges of the little 
toe. The metatarsal bone of the little toe is characterized 
by an enlarged base; this forms a marked projection 
which can be readily felt at the middle of the outer border 
of the foot. Tracing the outline of the inner border of 
the foot, the os ealcis can be recognized on the inner side 
of the heel : below and in front of the inner ankle the sus- 
tentaculum tali of the os ealcis and the astragalus can be 
felt; in front of the latter the projecting inner border of 
the navicular bone, called the tuberosity, can be easily dis- 
tinguished ; lying in front of this is the internal cuneiform 
articulating anteriorly with the base of the metatarsal bone 
of the great toe : this joint corresponds pretty closely to the 
middle of the inner border of the foot, reckoning the distance 
from the heel to the tip of the great toe. In front, the head 
of the metatarsal bone articulates with the first phalanx of 
the great toe, which in turn supports the terminal phalanx 
of that digit, there being only two phalanges in the great 
toe in place of three as in the others, an arrangement 
which corresponds with what we have seen in the case 
of the thumb. The joint between the metatarsal bone and 
the first phalanx of the great toe is supported beneath 
by two small nodules of bone ; these are called sesamoid 
bones, and the whole joint so formed corresponds to what 
is known as the ball of the great toe. The bones which 
form the outer and inner columns of the foot, above referred 
to, are themselves united together by joints and ligaments, 
with the exception, of course, of the bones of the toes, which 
are not laterally united to each other (Fig. 176). 

Just as the bones of the hand were arranged so as to 
form the hollow of the palm, so the bones of the foot are 
united together to form a series of longitudinal and 
transverse arches, which curve the sole in such a manner 
that the whole of its surface is never in contact with the 



34^ 



Arches of the Foot 




o-rouud. The best way by which to demonstrate this is to 
wet the foot by dipping it in water and then step on a dry 
lioor ; the wet imprint left when the foot is lifted represents 

accurately the surface of the sole which 
has touched the ground. From this it 
appears that the heel, the outer border 
of the foot, the fore part of the foot 
corresponding to the ball of the great 
toe, and the pads which cover the under 
surface of the other metatarso-phalan- 
geal joints have all been in contact with 
the floor, whilst the part corresponding 
to the interval between the heel and 
ball of the great toe, lying along the 
inner border of the foot, has not touched 
the ground, as is evidenced by the fact 
that the floor corresponding to this 
part of the sole is dry. 

Again, it must have been the experi- 
ence of every one when trying on a 
new boot that the fit was apparently 
comfortable and perfect so long as the 
foot was raised, but on placing the foot 
to the ground and throwing the weight 
of the body on it, the boot, which other- 
wise appeared to fit the wearer, then 
felt cramped and tight; this at once 
brings home the fact that under these 
difierent conditions the shape and size 
of the foot alter considerably ; in other 
words, the foot spreads out- when the 
weight of the body is thrown upon it : 
It lengthens, the toes being pushed further into the point 
ol the }K)ot, 1111(1 il becomes wider, as is proved by the 
tiKhtuesH across the instep (see Fig. 177). 



Fig. 177. Outlines 
of the imprint of the 
sole of the foot. The 
dotted line shows the 
outline of the sole of 
the foot wlirn it merely 
rests without pressure 
on a ])lane surlace. 
The thick black line 
repreKcnts the same 
when the weight of 
the body rests on 
the foot. The latter 
outline is longer and 
broader than the for- 
mer, which ahows how 
the foot expands in all 
it* dJaniet< 18 wIkmi it 
i» nubject«(l to pns- 
tiuri". 



Arches of the Foot 347 

It is important that the reader should be familiar with 
the mechanism by which these changes are effected. As has 
been stated, the bones of the foot, apart from those Oif the 
toes, are arranged in a series of transverse and longitudinal 
arches ; the former are apparent, as they form the rounded 
contour, from side to side, of the upper surface of the foot. 
The concavity of these transverse arches assists in forming 
the hollow of the sole. 

The experiment with the wetted foot has demonstrated 
the existence of a longitudinal arch, of which the posterior 
pillar is the prominence of the heel, the anterior pillar 





Fig. 178. " Fig. 179. 

Diagrams to illustrate the arches of the foot. 

a. The longitudinal arch. 

6. The transverse arch through the cuneiforms and cuhoid. 

corresponding to the ball of the great toe and the pad of 
the fore part of the foot immediately external to it : the arch 
between these two points coincides with the inner border of 
the foot, which is raised from the ground. The existence 
of these arches imparts a certain amount of elasticity to 
the foot ; they are like curved springs the extremities of 
which are in contact with the ground : if over the most 
elevated part of the spring pressure be applied, the result 
will be that the spring will spread out, its extremities will 
be more widely separated, and the distance between the 
highest point of the curve of the spring and the ground 
will be reduced. The arches of the foot act very much 



3^8 Arches of the Foot 

in the same way ; they spread out when the weight of the 
body is thrown on the foot, but they recover themselves at 
once when the pressure is removed. The elasticity thus 
imparted to the foot is of the greatest service in enabling 
it to withstand the violent shocks to which it is so fre- 
quently subjected. A little experiment will bring this 
home to the reader. In jumping from a height one lands 
ordinarily on the ball of the foot, the heel being the last 
part to touch the ground ; the shock is thus much reduced 
before the force is transmitted up through the leg : but if 
in place of landing on the fore part of the foot the reader 
jumps from an inconsiderable height and lands on his 
heels, with the knees extended, he will realize how un- 
pleasant the shock is by the jarring effect which it produces ; 
a height of a few inches is quite sufficient to cause results 
unpleasant enough to produce a lasting effect on the 
memory. In this case the arches of the foot cannot yield 
to the force, and so the shock is directly transmitted 
through the heel-bone and astragalus to the bones of the leg. 
Apart from the elasticity which is thus imparted to the 
foot, these arches also serve a useful purpose in protecting 
the nerves and vessels of the sole from the baneful effects 
of pressure. The reader will now realize how these struc- 
tures, as they lie in the hollow behind the inner ankle, pass 
down into the sole under cover of the arch which raises the 
inner border of the foot from the ground. 

The lesson to be learnt from these observations is that 
the foot when it supports the weight of the body on the 
ground is longer, broader, and flatter than when raised, in 
wliich position, the strain being taken off the arches, the 
foot becomes more curved and the elevation of the instep 
more pronounced. 

A« man only exceptionally makes use of the foot asapre- 
hengjle organ, th(3 reader will note that that part of the foot 
(». e. the toes) which corresponds to the most movable segment 



Dorsum of the Foot 349 

of the hand — the fingers — is much reduced in size : moreover, 
owing to the fact that in the foot the further extremity 
of the metatarsal bone of the great toe is united to the other 
metatarsal bones, we have no such power of opposition of 
the great toe with the other toes as we possess in the thumb 
and fingers, for in the hand the distal end of the metacarpal 
bone of the thumb is free and unconnected with the other 
metacarpals. 

The dorsal surface of the foot owes its form in great part 
to the arrangement of the bones. Overlying these are the 
tendons which are passing down from the anterior surface 
of the leg in front of the ankle. As previously described, 
the tendon of the anterior tibial muscle may be traced 
from the inner side of the front of the ankle down to the 
middle of the inner border of the foot ; in like manner the 
tendon of the peroneus tertius, the muscle which is intimately 
associated with the lower fibres of origin of the long 
extensor of the toes, may be traced from the ankle imme- 
diately in front of the lower end of the fibula to the middle 
of the outer border of the foot, where it is attached to the 
base of the metatarsal bone of the little toe on its upper 
surface : this tendon is small and thin, and only exceptionally 
gives any indication of its presence by a corresponding 
surface elevation. Between the foregoing muscles as they 
lie on either side of the front of the ankle are . placed the 
tendons of the long extensor of the toes and the special 
extensor of the great toe. The former, which are four in 
number, pass to the dorsal surfaces of the four outer toes, 
whilst the latter, which is single, passes down to the dorsum 
of the great toe! Above, at the front of the ankle, the 
tendons are .confined within narrow limits ; below, on the 
dorsum of the foot, they spread out as they pass forwards 
to reach the toes (Pis., pp. 216, 328). 

If the reader will place his finger on the dorsum of his 
own foot, in front of the outer ankle, he will recognize that 



350 Short Extensor of Toes 

something soft and of considerable thickness here overlies 
the tarsal bones and prevents him from recognizing as 
easily as elsewhere their details. This is a muscle, called 
the short extensor of the toes: it arises from the fore 
part of the os calcis or heel-bone and the hollow between 
it and the astragalus, from the outer side of the os calcis 
in front of the groove in which the peroneus brevis is 
lodged, and also from the anterior annular ligament : the 
muscle at its origin therefore lies immediately in front of, 
and below, the prominence of the outer ankle. The fleshy 
part of the muscle is placed obliquely across the dorsum 
of the foot from without inwards, ending in four small 
tendons which pass to the four inner toes. The tendon 
to the great toe is inserted into the base of the first 
phalanx, the other tendons blend with those of the long 
extensor muscle which pass to the second, third, and fourth 
toes. As the muscle crosses obliquely over the dorsum of 
the foot it is overlain by the tendons already enumerated, 
with the exception of the special extensor of the great 
toe and the tibialis anticus, which lie altogether to its 
inner side. 

It is to the presence of this muscle that the fullness of 
the dorsum of the foot in front of the external malleolus 
is duo. The tendons which cross it, particularly the tendon 
of the peroneus tertius, help to restrict its influence on 
the 8uriaco contours; but in the interval between the 
poroncus tertius in front, the external malleolus behind, 
and tlio tondon of the peroneus brevis below as it passes 
to the spur of the metatarsal bone of the little toe, the 
liffshy part of the muscle forms an oval elevation, which 
iH considerably intensified when the toes are forcibly ex- 
tended (Pis., pp. 216, 318, 328, 338, 366). 

Thr, appoaranco of the back of the foot will vary 
lu-cordm^r to t},r, amount of subcutaneous fat present; if 
that is considorablo in quantity, the outlines of the various 



Muscles of the Foot 351 

tendons are masked, and only become apparent when 
the muscles are strongly contracted. Similarly with the 
veins which usually form a feature of some prominence 
on the back of the foot; they are best seen in a model 
of spare habit, where their presence is indicated by their 
surface projection ; when embedded in a layer of sub- 
cutaneous fat their outline is displayed rather by colour 
than by relief. As the arrangement of the veins of 
the lower limb will be described hereafter, it is not neces- 
sary at present to refer further to them. 

As in the hand, so in the foot, the intervals between the 
metatarsal bones are occupied by muscles called interossei ; 
these serve to maintain the uniformity of the surface con- 
tours and prevent an undue definition of these bones of 
the foot. 

The under surface of the bones of the foot is provided 
with many muscles ; these are arranged for the purpose 
of anatomical description into layers, but a knowledge of 
their details is happily unnecessary. The muscles which 
have most influence on the surface form are naturally those 
which are immediately covered b}^ the skin and fascia 
of the sole. The three most important arise posteriorly 
from the under surface of the prominence of the heel. Of 
these, one passes forward along either border of the foot, 
whilst the third occupies an intermediate position. 

The abductor hallucis, or abductor of the great toe, arises 
behind from the inner side of the under surface of the 
bony prominence of the heel. Its fibres pass forwards 
along the inner border of the foot, forming a fleshy 
longitudinal prominence. Anteriorly the muscle is in- 
serted into the inner of the two sesamoid bones, which 
are placed one on either side of the under surface of the 
joint between the metatarsal bone and first phalanx of 
the great toe (Pis., pp. 318, 338). 

The abductor minimi digiti, or abductor of the little toe, 



352 Muscles of the Foot 

arises behind from the outer side of the under surface of 
the bony prominence of the heel. As its iiesh}^ fibres pass 
along the outer border of the foot they are attached to 
the prominent tubercle of the base of the fifth metatarsal 
bone. Anteriorly the muscle is inserted into the base 
of the first phalanx of the little toe along with the short 
flexor of that digit. The fleshy part of the muscle forms 
the surface elevation along the under surface of the outer 
border of the foot, between the heel-bone behind and the 
prominent spur of the fifth metatarsal bone in front, as 
well as along the outer and under surface of that bone. 
In standing on the foot this border is in contact with 
the ground, and is compressed and flattened by the weight 
thrown on it (Pis., pp. 318, 338). 

The action of these two muscles is indicated by their 
name. Only here it is necessary to warn the reader that 
the terms adduction and abduction of the toes apply to 
movements whereby the toes are drawn to, or away from, 
a line passing along the axis of the second toe, and have no 
relation whatever to the middle line of the body. 

Occupying the interval between these two muscles, 
and lying along the middle of the sole of the foot, is 
the flexor hrevis digitorum, or shoi't flexor of the toes. 
This arises behind from the under surface of the pro- 
minence of the heel-bone, between the two muscles just 
dftHcribed. In front, it ends in four tendons, which pass 
to tho four outer toes, there to be attached to the bases of 
tho8»'C(,nd phalanges on their under surfaces. The fleshy 
part of the muscle occupies the central part of the sole ; 
in the intervals on either side of it, and in front, some 
of the short muscles of the great and little toe come in 
roUtion to tlio surface. It is not necessary to dwell on 
these detailH further than to point out that to the sesamoid 
honoH at tl)*, 1kis(. of the great too there are attached 
the short flexor and iid.hictors of that digit, whilst on the 



Plantar Fascia 353 

outer side of the sole, the short flexor of the little toe 
unites with the abductor of that digit to be inserted into 
the base and outer border of the first phalanx of the 
little toe. The action of the short flexor of the toes is 
sufficiently indicated by its name ; it assists the long flexor 
in bending the toes towards the sole of the foot. 

The influence of these muscles on the surface forms 
of the sole is less than what one might expect, owing to 
the fact that the skin in this region is very thick and 
tough, and also because there is a considerable quantity 
of fat and a layer of dense fascia overlying them. 

The 'plantar fascia very much resembles the fascia which 
has been already described in the hand. It consists of 
a very strong and thick central portion which covers 
the short flexor of the toes, and two thinner lateral expan- 
sions which spread over the abductors of the great and 
little toes respectively. The strong central part, which is 
connected with the under surface of the heel behind, 
and with the anterior extremities of the metatarsal bones in 
front, is a structure of no little importance, as it assists 
in maintaining the longitudinal arch of the foot by tying 
together its two extremities. The subcutaneous fat of the 
sole of the foot is specially modified to enable it to serve 
the purpose of an elastic pad. The fatty lobules, which 
are of small size, are abundantly mixed with fibrous tissue, 
which imparts to the layer so formed a remarkable tough- 
ness and resiliency. This layer is especially thick over 
those parts of the sole on which the bulk of the weight 
rests, particularly over the heel and the ball of the great 
toe. The skin which forms the superficial covering is 
likewise modified. In no part of the body is it so 
thick as over the heel, and an inspection of the sole 
of the foot will reveal the fact that over all the parts of 
the sole which touch the ground the skin is thick and 
horny, whereas where the foot is not in contact with 

THOMSON A a 



or^ Sole of the Foot 

the ground the skin is thinner and more delicate, as is 
indicated by its colour and wrinkling. 

The hollow of the sole, which is continuous with the 
hollow behind the inner ankle round the inner border of 
the foot, occupies the interval between the surface of the 
heel which is in contact with the ground behind and the 
ball of the great toe in front. The latter projection corre- 
sponds to the metatarso-phalangeal joint of that digit, 
a joint which is greatly enlarged owing to the presence 
of the two sesamoid bones already referred to. This forms 
a well-marked oval elevation, around which the hollow 
of the sole curves slightly before it is interrupted in front 
by the pad of the fore part of the foot which corresponds 
to the metatarso-phalangeal joints of the remaining toes. 
Externally the hollow of the sole is bounded by the outer 
border of the fo6t which is in contact with the ground 
when standing. 

The toes, with the exception of the great toe, are 
much bent, so that when viewed from the under surface 
little can be seen of their shafts except the enlarged extre- 
mities by which they rest on the ground ; the pad of the 
fore part of the foot is therefore separated by a deep groove 
from the enlarged ends of the toes. In correspondence with 
this, the dorsal surfaces of the toes are more or less curved 
in an antero- posterior direction. 

^lodols with good feet are exceedingly difficult to find. 
Thft habit of wearing boots is so universal amongst civilized 
raco.s, that it is difficult to meet with a person whose feet have 
not boon tortured and disfigured by this means, and in the 
peasantry of our own islands who habitually go barefooted 
the exposure and injury to which the feet are subjected do 
much to destroy their natural beauty : we are largely depen- 
d<Tit tlierefore for our ideal on our knowledge of the antique. 
In regard to the length of the toes, there is much diversit;^ 
of opinion. The type most frequently represented in the 



The Toes 355 

antique is that ia which the second too projects beyond 
the great toe. As a matter of fact, this condition is more 
frequently met with in dwellers of the south, for observa- 
tions made on our Highland peasantry, some of whom have 
gone about barefooted from childhood, appear to indicate that 
the great toe is almost universally the longest of the series : 
this is a detail, however, of little moment, and the choice 
may well be left to the individual taste of the artist. The 
third toe is shorter than the second by the length of 
the nail, the fourth hardly reaches the level of the nail 
of the third, and the fifth presents many variations in 
length ; there is anatomical evidence that this toe is 
gradually undergoing a reduction in size. 

In regard to the direction of the different toes a certain 
misconception appears to exist. The ' Anatomical bootmaker ' 
would have us believe that the inner borders of the foot and 
great toe are in line when the foot is at rest. An examina- 
tion of the best models appears to upset this view, for 
normally the great toe has a slight outward inclination, 
though undoubtedly this is oftentimes unduly exaggerated 
by the wearing of pointed boots. The student, however, 
should clearly understand that we possess a limited power 
of abducting and adducting the great toe at the metatarso- 
phalangeal joint. The second and third toes as a rule should 
follow this outward inclination, whilst the fifth should be 
slightly inturned, the direction of the fourth being more or 
less straight, or directed slightly inwards or outwards, as the 
case may be. 

The cleft between the great and second toes is often- 
times a little deeper than that between the second and 
third. As a rule, the clefts between the four outer toes are 
linear, whilst that between the great and second toe is 
wide : this may be well seen in an infant's foot, particu- 
larly when the toes are outspread. Advantage was taken 
of this wider interval between the great and second toes 

A a 2 



0-6 Female Foot 

to pass the thong by which the sandal was held in position. 
The toe's appear longer when viewed from above than 
when seen from below; this is due to the web between 
the toes sloping downwards and forwards towards the sole. 

As the bones of the leg are firmly fixed together, 
there is no movement in the lower limb comparable 
to the movements of pronation and supination which 
occur in the fore-arm. This necessarily limits the range 
of the movements of the foot as compared with those of 
the hand. Apart from the movements which have been 
described as taking place at the ankle-joint, the foot may 
be turned inwards or outwards ; in the one case the sole 
is inverted, in the other everted ; the range of motion in 
the latter direction is the more limited. These movements 
take place at the joints between the tarsal bones. The 
toes may be flexed or extended as well as moved apart 
and drawn together ; this latter movement is freest between 
the great and second toe. 

The foot of the female is absolutely smaller than that 
of the male. If we take into consideration its proportion 
to the lieight, we find that it is relatively slightly shorter 
in women. A foot unduly small, if represented in the 
nude, at once imparts a feeling of instability to the figure. 
Ill no respect do artists concede more to fashion than 
in the representation of the female foot: one has only to 
imagine what the same foot would look like if divested 
of its coverings to realize to what absurdities this 
sacrifice of truth may lead. Another point on which the 
lay mind is apt to be misled is the height of the instep. 
Tho foot as it rests within the boot is really supported 
on an incline, the slope of which depends on the height 
of the heel : this tends of course to emphasize the arch 
on the dorsum of the foot, as the toes are necessarily some- 
what bent upwards at the metatarso-phalangeal joint. The 
rciader neorl eiily notice the appearance of a foot in a high- 



Superficial Veins of Leg 357 

heeled shoe to realize this fact. Naturally when the same 
foot is bared and placed flat upon the ground the curvature 
of the instep is much reduced; so marked is the change 
that I have frequently been struck with the criticism 
passed on photographs of fairly well-formed feet, to the 
effect that they were unduly flat. 

True flatness of the foot must of course be avoided, but 
the student will readily recognize this condition, as he 
will notice that the sole of the foot not only touches 
the ground at the surfaces already described, but is in 
contact with it at the parts corresponding to the inner 
border and hollow of the sole. Whilst undue flatness of 
the foot is ngly, the other extreme, excessive arching of the 
instep, should be avoided, as it imparts a cramped appear- 
ance to the foot. 

Great variation will be met with in the length and 
breadth of the foot. As a rule, the width of the foot is 
about one-third of its length. Excessive prominence of 
the heel, which is associated with marked curving of the 
tendo Achillis as it passes down to it, should also be avoided, 
as it gives rise to an unpleasant outline. 

The smaller bones, the greater abundance of fat, and the • 
less marked muscular development impart to the female foot 
a softer outline and a plumper form. 

Much that has been already stated in regard to cutaneous 
veins in general might be repeated here, but the reader 
is referred to p. 217, where the matter has been previously 
discussed. The blood in the veins of the leg flows con- 
trary to the direction of the force exercised by gravit}^ ; 
in consequence there is a much greater tendency for the 
blood to accumulate in these vessels than in the upper 
limb, where the flow of the blood through the veins is 
frequently accelerated by the raising of the arms. In the 
lower limb we meet with the longest vein in the body; 
it extends from the inner ankle up the inner side of 



358 Superficial Veins of Leg 

the leg and tliigh, and terminates above a little below the 
inner extremity of the fold of the groin. It is superficial 
throughout its entire length, and when distended with 
blood it forms a well-marked surface elevation, as may be 
seen in the thighs of the Fighting Grladiator. Over the 
dorsum of the foot a more or less arched arrangement 
of the veins is readily recognizable, whilst running up the 
outer side of the ankle and back of the leg to reach 
the hollow behind the knee is another vein, which is pretty 
definite in its position. These veins are called respectively 
the inner or long saphenous and the outer or short saphenous 
veins. They will be seen best as surface elevations 
when the model is of spare habit and when the limbs 
are in action, as under these conditions they are dis- 
tended. The student is warned that these veins are often 
unduly prominent and tortuous, an appearance which 
depends on their abnormal distension or varicose condition ; 
hence care must be exercised to avoid a too realistic 
representation of them. In the antique they are employed 
to emphasize powerful muscular action, and the student 
cannot do better than follow the example set before him 
in these masterpieces of plastic art. 

When the type is less athletic and the subcutaneous fat 
more abundant, the veins are indicated by colour rather 
than contour, a condition which particularly obtains 
in the female, in whom their representation as surface 
elevations would bo altogether out of keeping with the 
character of the fin-Qro. 



CHAPTER Xri 



THE NECK 

In considering the anatomy of the neck it will be 
necessary in the first instance to examine the skeleton 
of this part of the body, and note how it is united with the 
head above. As was stated in a previous chapter (see 
ante^ p. 36), there are seven cervical or neck vertebrae in 
that part of the * back-bone ' which passes through and 
supports the soft tissues of the 
neck. One of the character- 
istic features of these neck 
vertebrae is the shortness of 
their spines: to this there 
is one exception, the last 
or seventh cervical vertebra. 
The reader's attention has 
been already directed to the 
importance of the spine of 
this vertebra as a surface pro- 
minence on the back of the 
root of the neck (see ante, 
p. 106), and the name, vertebra 
prominens^ often given to it, 




Fig. 180. Skull and cervical ver- 
tebrae of man, showing small face- 
bones, large brain case, and short 
cervical spines. 



refers to this peculiarity in the length of its spine. In 
regard to the other neck vertebrae,' the shortness of their 
spines is a distinct advantage, as it enables the vertebral 
column to be more fully extended, i. e. bent back, in this 
situation than in any other region. The two highest of 
the neck vertebrae are modified in a peculiar way to adapt 



26o The Atlas and Axis 

them for articulation with the skull. It is not necessary 
that the student should be familiar with the details of 
structure of these two vertebrae, as they have no influence 
whatever on the surface forms, but some account of the 
nature and range of motion possible at these joints is of 
service in enabling the reader to understand the subsequent 
account of the movements of the head and neck. 

The highest of the cervical vertebrae is called the ailas^ 
owing to the circumstance that it supports the globe of the 
head : it is provided with a pair of peculiar articular surfaces 
on which rest the condyles of the occipital bone, one 
of the bones forming the base or under surface of the 
skull. These condyles may be compared to the rockers 
on a cradle, and as they move in the hollows on the upper 
surface of the atlas they produce a rocking or nodding 
movement of the head. Associated with this there may 
be slight degrees of oblique or lateral movement. 

The atlas fits on the vertebra beneath it — the axis, so 
called — very much as a ring fits over a peg, for the latter 
vertebra is provided with an upstanding process called 
the odontoid or tooth-like process, which is enclosed above 
in a ring formed by the bony arch of the atlas together 
with a ligament. The joint is a pivot joint, and here take 
place the movements of rotation whereby the head, and 
with it the atlas, are turned from side to side. The range 
of these movements is checked by ligaments, but as a rule 
the head may be rotated to one or other side of the middle 
plane of the body to the extent of 30". The reader will thus 
realize the importance of these two joints, as at the upper 
the nodding movements alone take place, whilst at the 
lower the movements of rotation only occur. 

In the remainder of the cervical portion of the vertebral 
column the principal movements are effected in a backward 
and forward direction; extension or bending backwards 
18 more free i\iiiii flexion or bending forwards, for the reason 



Movements of the Neck 



361 



explained at the commencement of this chapter, and also 
because the forward movement is checked when the chin 
comes into contact with the front of the chest. The other 
movement of which this part of the 
column is capable is a combination of 
rotation and lateral flexion^ a movement 
whereby we bend the neck to the side. 
The neck vertebrae are so surrounded 
on all sides by muscles and other tissues 
that under ordinary conditions they 
have no direct influence on the surface 
forms, with the single exception of the 
spine of the vertebra prominens. Be- 
hind and on either side it is principally 
muscle which we have to deal with, 
whilst in front the gullet, windpipe, 
and larynx all conceal the form of the 
bony structures. The fleshy mass met 
with behind is a continuation upwards 
of that great group of muscles which 
has been already described under the 
name of the erectores spinae (see ante, 
p. 41): the latter was seen to occupy 
the furrows on either side of the spines 
of the lumbar and dorsal vertebrae, but 
became much reduced in bulk in the 
mid-dorsal region : above that point, 
however, the muscular column is rein- 
forced by additional slips, all more 
or less intimately associated with the 
movements of the head and neck. 
See Fig. 181. These form two cylin- 
drical masses which pass up to reach tli2 under surface of 
the back of the skull on either side of the short spines of 
the cervical vertebrae which, in consequence, have no direct 




Fig. 181. A diagram 
to show the arrange- 
ment of the muscles 
which support the 
back-bone. The mus- 
cles, which are repre- 
sented in solid black, 
are seen to be thick 
in the regions of the 
loins and neck, and 
comparatively thin in 
the mid-dorsal region. 



362 



Muscles of the Neck 



influence on the surface contours. The fleshy columns on 
either side are separated from one another by a fibrous 
partition called the Ugamentum nuchae, a feeble representa- 
tive in man of the stout elastic ligament so often met with 
in many of the lower animals. As was stated in an earlier 




Fio. 182. View of tlic muscles attached to the shoulder-blade. The 
trapezius has been cut away on the left side of the figure. 

a. TraiK'ziuH muscle. 

0, Ulioiiilxjid. 

e. Klovator of tho angle of tlie scapula 

(levator anguli flcapulao). 
fi S|i|«niu» imiHj'lc. 



«■ Compli'Kua mugclo. 



/. Sterno-mastoid muscle. 

g. Infra-spinous fossa on back of scapula. 

h. Acromion process of scapula. 

i. Spine of scapula. 

j. Collar-bone (clavicle). 

k. Humerus. 



<!hu|.t.T (CImpt..,- J, p. 21), the poor development of this 
">?'""<^>it in man is associated with the assumption of the 
erect posture, a position in which the head is almost 
Dalanced .,n the sunnnit of a vertical column, whereas in the 



Ligamentum michae 



363 



lower animals the ligament is of necessity strong in order 
to support the head at the 
extremity of a more or less 
horizontal column. 

It is needless to enter into 
any detailed account of these 
fleshy masses on the back of 
the neck, as they are in 
great part overlain by the 
trapezius, which has been 
already described (p. 105), as 
well as by other superficial 
muscles, to be hereafter dis- 
cussed ; but their indirect 
influence on the surface con- 
tours of the back of the neck 
should not be overlooked, 
as it is to their presence that 
this region owes its full and 
rounded appearance. 

The form of the front of the 
neck is partly due to muscle 
and partly to other structures 
which are associated with the 
alimentary tract and the re- 
spiratory system. In front of 



a. Placed over tendinous part of erector 

spinae. 
6. Posterior superior iliac spine. 

c. Haunch-bone (os innominatum). 

d. Socket for head of thigh-bone (aceta- 

bulum). 

e. Tuberosity of the ischium. 

f. Placed over fleshy part of erector 

spinae. 

g. Splenius muscle. 

h. Mastoid process of temporal bone, 
t. Complexus muscle an d superior curved 
Line of occipital bone. 




Fig. 183. Shows the great erector 
mass of muscles. The muscles are 
shown only on one side ; the groove 
in which they are lodged is seen 
on the right side of the figure. 



3^4 



Deep Structures of Neck 



the vertebral column, and commencing above at the back 
of the mouth, is the tube, called the gullet or oesophagus, by 
which food is transmitted to the stomach. Within and 
below the arch of the lower jaw there is the Tiyoid hone, 
which is connected with the root of the tongue. Below the 

hyoid bone, and lying in 
front of the gullet, is 
the trachea or windpipe. 
The upper extremity of 
this respiratory tube is 
peculiarly modified to 
form an organ imme- 
diately concerned in 
voice-production — the 
larynx. In front of the 
windpipe, and below the 
level of the larynx, there 
is a gland of considerable 
size called the thyroid 
body. Connecting the 
hyoid bone and larynx 
with surrounding parts, 
such as the lower jaw- 
bone, the breast-bone, 
and collar-bones, there 
are a number of small 
muscles which, whilst 
they do not as a rule 
infiuence the surface 
forms in detail, yet in 
liulk assist in imparting to the front of the neck its charactcr- 
iHtic modelling. A more detailed description of some of 
these structures is necessary. 

The hyoid hone, or bone of the tongue, which is a small 
slondor bone formed like a (J, is situated at the angle formed 




Fio. 184. Diaf,niini to show the position 
of Kome of thti structures in the neck. 

n. Hyoid iKino. 

b. Thyroid cartilngo of tlie larynx (Adam's 

apploi. 
c Ixjft IoIkj of thyroid gland. 
•/ IppcT ond of broast-hone. 
r Tracht-a or windpipe. 
/. Spino of iiovonth cervical vertebra (vertebra 

proifiin<'ti8). 



The Hyoid Bone 365 

by the outline of the soft parts below the chin and the 
line of the front of the neck. The position of the bone 
varies according to the position of the head. When the 
eyes are directed straight forwards the hyoid bone lies 
nearly on a level with the angle of the lower jaw. The 
reader may satisfy himself as to the position of the bone 
by grasping the tissues of the neck in this region firmly 
between the thumb and fingers. When the head is 
extended or thrown back, the angle formed by the line 
below the chin and the line of the front of the neck is 
opened out, and the position of the bone is more easily 
recognized ; it always corresponds to the line of flexure 
or angle where the head bends forward on the neck. 
When the head is thrown back the first point of resistance 
met with, in passing the finger from the chin downwards 
along the middle line of the neck, is the hyoid bone. 

About half an inch below the level of the hyoid bone 
a well-marked elevation will be easily recognized : this 
projection is due to one of the cartilages of the larynx or 
voice-box. It is called the pomum Adami, or Adams apple, 
and is usually more prominent in the male than in the 
female. In the adult it is large as compared with that in 
the child. If the neck of a child be examined there is 
little or no evidence of its presence, but at that period of 
life when youth gradually merges into manhood, changes 
take place in the growth of the larynx which are associated 
with marked increase in the size of its cartilages, and 
their surface outlines become factors of importance in the 
modelling of the throat. This alteration in the size of the 
larynx is intimately associated with the changes which are 
taking place at the same time in the character of the voice, 
changes which are popularly referred to as the ' breaking 
of the voice '. In the female there is no such marked 
difference between the forms displayed in the child and the 
adult, so that in woman the rounded contours of the front 



366 



iJ 



W 



Rectus 
abdominis.. 



A nt. sup- 
iliac spine.- 
Aponcur.of 
ext. oblique. 

Sartm-ius: ' ' 

Rectus 
fcmoris. --~ 



Vastus int.. 

Sartorius. ■ 

Band of Richer. ...> 
Rectus femoris. -. 
Vastus externus 
Int.condyle of femur. 
Patella. ,,„ 

Ligamentum patellae. ■■ ' ' \v!-/ 

Sartorius: 
Itbia, subcutan. surface. 

Gastrocnemius: • 

Tibialis anticus. 

Soleus: 

FUxor longus digit. pedis. , . 

Tendo A chillis.. 

Tibialis posticus. .. 
Internal malleolus [tibia )r ■ 
lutniml annular ligament. 
J il'i.ilis anticus. 



■External oblique. 

-Erector spinae, tendinous part. 

~ ' 'Iliac crest. 

Gluteus medius. < 

- - ' " 'Tensor fasciae femoris 

Trochanter major, 

\ Gluteus maximus, 

- - - -Ilio-tihial band. 
,'/ Vastus externus. 

_ -'Biceps cmris, long head. 

^ . -Band of Richer. 

.^Biceps cruris, short head. 
^-Vastus externus. 
^ ''External condyle of femur. 
,' Patella. 

' ypat. 

. , , Head of fihila. 
_ . - - Tlio-tibial band. 

-Tubercle of tibia. 
...-Soleus. 

-Gastrocnemius. 



Ti 
anticus. 

Long ext. 
oftoes. — -^- 

Long extensor 
of great toe: 

Ant. annular lig: 
Ext. malleolus. ' 
Ext. digit, brevisr ' ' 



■Peroneus 
longus. 

Peroneus 
brevis. 

Tendo 
A chillis. 



i 



Thyroid Body .367 

of the neck are not as a rule disturbed by any undue pro- 
jection of these laryngeal cartilages. 

Below the larynx, the windjpipe, which is composed of a 
number of cartilaginous ringsunited together by membrane, 
passes down behind the upper end of the breast-bone to 
enter the thorax. On either side of this tube, which, owing 
to its structure, always remains open or distended, there 
are the lobes of a structure called the thyroid body. These 
consist of masses of gland tissue of oval flattened form which 
lie on either side of the trachea, and which are connected 
with each other anteriorly by a bridge of gland substance 
called the isthmus, which passes across the front of the 
windpipe just below the larynx. These structures lie under 
the layer of thin muscles which pass up from the breast and 
collar-bones to be attached to the hyoid bone and larynx 
above, and serve to increase the fullness of the neck in this 
region. As the thyroid gland is usually larger in the 
female than in the male, it assists in imparting that round- 
ness and fullness to the lower part of the neck in the female 
which is regarded as so charming a feature in its modelling. 
The reader is warned that undue emphasis of this feature 
may give rise to an unnatural form, a form which is by 
no means uncommon and is associated with the diseased 
enlargement of the gland called goitre. 

These structures, as has been stated, are some of them 
overlain by thin muscles, whilst others are supported and 
fixed by the same means. A detailed description of these 
appears unnecessary, as it is only under exceptional circum- 
stances that they can have any direct influence on the 
surface forms : thus it is only in the emaciated, or in such 
extremes of muscular effort as are associated with the 
struggles of an unfortunate creature gasping for breath, that 
their details are at all apparent. 

The muscle which plays the most important part as 
a determinant of the surface form of the neck is the sterna- 



368 



The Sterno-mastoid 



mastoid. 



Inferiorly this muscle is attached to the anterior 

surface of the upper end of 
the breast-bone by a thick 
rounded tendon ; it also 
derives fleshy and tendi- 
nous fibres from the inner 
third or so of the collar- 
bone; these two origins are 
separated by an interval of 
variable width. The fleshy 
belly formed by the union 
of these two attachments 
passes upwards and back- 
wards towards the part of 
the skull immediately be- 
hind the ear. If the finger 
be placed on the bone in 
this situation, a thick 
rounded blunt process can 
be distinctly felt : this is 
called the mastoid process 
of the temporal bone, and 
it is into this and the 
rough ridge passing back 
from it, called the superior 
curved line of the occipital 
hone, that the muscle is 
inserted. The extent of 
the attachment of the 
muscle to this ridge varies 
considerably in diff"erent 
individuals (Fig. 185, and 
Pis., pp. 58 72, 86, 152, 
382, 410). 
Iho stemo-inastoid as it passes obliquely across the side 




Fio. 185. Diagram showing the 
arrangement of some of the principal 
structures of the neck. 



n. Rtorno-mastoid muscle. 
'». Trapozius muscle. 
'•. Storno-liyoid muscle. 
d. I»wcrjaw. 
'. Hyoid bone. 
/. I'o«tf-rior trianpjle. 
0- Annirnion prorc-ss of scapula. 
h. Rpino of Bciipula. 

I I. The two hollios of the omo-liyoirl muscle. 
j Thyroid cartilafjo of larynx (Adam's 
npplf.). 
I- k. Tlio two boUiofl of the digastric muscle, 
m. MnnU.id procoss of temjioral bono. 
II. 8ai*rior curved line of occipital bone. 
p. HumoniH. 
r. Kimt rib. 

». r<»riiroid procoBR of scapula. 
r. IMm-».don infra-Hpinoua fossa of scapula. 
r '*<»lbir-U»ii«. 
I/. Iln-anf-bonn. 



The Sterno-mastoid 



369 




of tlie neck divides that region into two triangles : tlie one, 
in front and above it, is called the anterior triangle, that 
behind and below it the posterior triangle. The conver- 
gence of the muscles of either side below, where they are 
attached to the upper end of the breast-bone, has a most 
important effect on the moulding of the surface forms : here 
their tendons of origin from the breast-bone lie just within 
the expanded inner extremities of the collar-bones as they 
rest upon the upper border of the sternum on either side. 
Thus a V -shaped recess is produced, the sides of which are 
formed by the tendons of the 
two sterno-mastoid muscles, 
whilst the angle of the V cor- 
responds to the upper border 
of the breast-bone. The depth 
of the recess is further em- 
phasized by the projection 
caused by the inner end of 
the collar-bone on either side. 
This depression corresponds 
to the surface hollow familiar 
to the reader under the name 
'pit of the necTc. In the male 
its borders are sharply de- 
fined, especially during vio- 
lent muscular effort ; in the 
female, owing to the presence of an abundant layer of fat 
beneath the skin,the outlines are smoother and more rounded, 
and the surface depression is altogether softer, and forms 
a feature of great* beauty in the modelling of the throat as 
it rises from the general fullness of the breast (Pis., pp. 
58, 62, 132, 148, 152, 298, 434). 

It is in the interval between the two sterno-mastoids that 
the structures already enumerated lie, viz. the windpipe, 
larynx, and hyoid bone. These, as we have seen, are 

THOMSON C b 



Fig. 186. Showing articulation 
of the collar-bones (clavicles) with 
the breast-bone (sternum). 

a. Collar-bones (clavicles). 

b. Sternal ends of collar-bones. 

c. Placed on the first and second ribs. 

d. The upper piece of the breast-bone 

(manubrium sterni). 

f. Rib cartilages. 

g. Placed over the body of the first dorsal 

vertebra ; lies in the interval between 
the sternal ends of the collar-bones, 
a space which corresponds to the 
surface depression at the root of the 
neck, called the pit of the neck. 



oyo Pit of the Neck 

covered by a layer of small muscles on either side. The 
interval between the sterno-mastoids above, which is 
bounded superiorly by the border of the lower jaw and 
inferiorly by the hyoid bone, is filled up in part by the 
muscles of the tongue and floor of the mouth, in part by 
blood-vessels, and in part by the salivary glands ; one of the 
latter occupies the interval between the ear and the angle 
of the jaw. Under cover of the angle of the jaw there is 
another of these glands, which imparts a fullness to the 
surface- as it sweeps inwards and downwards towards the 
hyoid bone (Plate, p. 410). 

In regard to the region behind and below the sterno- 
mastoid, the student should recollect the arrangement of 
the superior fibres of the trapezius — that muscle arises 
above from the back of the base of the skull close to the 
middle line behind, and passing downwards, outwards, and 
forwards, is inserted into the outer third of the upper 
border of the collar-bone. There is thus an interval between 
the anterior border of the trapezius and the posterior 
border of the sterno-mastoid, and this space constitutes the 
posterior triangle of the neck, the base of which corre- 
sponds to the middle third of the collar-bone, the summit 
to the interval between the attachment of the muscles to 
the superior curved line above, whilst the floor is formed 
by the deeper muscles, which are here superficial and are 
thus brought in direct relationship to the surface. So dense 
and tough, however, is the fascia which covers them, and so 
tliick the layer of fat, that their details are hardly, if at all, 
apparent on the surface. The boundaries of this space, 
constituted as they are by the posterior border of the 
st<>rno- mastoid anteriorly, and behind by the anterior edge 
of the trapezius, form in muscular males and thin-necked 
fnmales outstanding surface contours which map out very 
clnarly the triangular interval referred to. Especially is 
this the case towards the lower part of the neck, where the 



Hollows above the Collar-hone 371 

clavicle forms a prominent ridge, the hollow above which 
corresponds to the interval between the two muscles : this 
depression is in marked contrast to the fullness below caused 
by the origin of the great pectoral and the deltoid muscle 
of the shoulder, though the interval between these is often- 
times indicated by a shallow furrow. These details, as has 
been said, are best seen in a spare athletic male ; in the 
female such evidence of structure is contrary to the usually 
accepted type, in which the general roundness of the neck 
is largely due to the abundance of fat ; but in women of 
a spare habit and with, slender necks these details, if 
not unduly emphasized, may be in harmony with the 
type represented (Pis., pp. 58, 62, 72, 132, 148, 152, 158, 
382\ 

The position of the shoulder-girdle has a marked influence 
on the production of this hollow ; in models in whom there 
is no evidence of this depression when the arms are hanging 
by the side we get clearer indications of its presence when 
the arms are raised and carried forwards (Pis., pp. 158, 
382). In this position the collar-bone is not only elevated, 
but carried forwards from the chest wall ; it is rendered 
more prominent, and the space is thus more clearly defined, 
though even under those conditions, especially in well- 
formed women in whom the subcutaneous fat is uniformly 
distributed, the surface contours are rounded and less abrupt 
than in the male. If the muscles be strongly developed and 
the action violent, one of the deeper muscles crossing the 
floor of the space not unfrequently forms an oblique surface 
elevation, which can be distinctly recognized passing across 
the interval between the sterno-mastoid and trapezius just 
above the collar-bone. This muscle is called the omo-hyoid : 
it has two bellies. The portion with which we are more 
immediately concerned arises from the superior border of 
the shoulder-blade, just internal to the root of the coracoid 
process. The anterior belly is attached to the outer part of 

B h 2 



372 



Hollows above the Collar-bone 



the lower border of the hyoid bone. These two small fleshy 
bellies are connected by an intermediate tendon which lies 
beneath the sterno-mastoid muscle (see Fig. 185). It is the 
posterior belly which forms the surface projection above 
referred to, and it passes obliquely upwards and forwards 
from under cover of the collar-bone, where th.e fibres of the 
trapezius are attached, in a direction corresponding to a line 
drawn from that point upwards and forwards towards the 

hyoid bone when the 
neck is outstretched. 
The student will re- 
cognize the surface 
form produced by this 
muscle on the right 
side of the neck of 
the Fighting Gladia- 
tor. An absence of 
fat in this region con- 
tributes to the clear- 
ness with which these 
details are seen. 

Not unfrequently 
in models of spare 
habit the lower at- 
tachments of the 
sterno - mastoid are 
very distinct. As has 
benn stated, tliero is an interval of variable width between 
Its origins from the breast-bone and collar-bone, and this is 
often roi)rosoiited on the surface by a triangular depression 
n^Is., pp. 58, 62, 72, 148. 152, and Figs. 187, 188, 189). 
An undue emi)hasis of these details is likely, however, 
to detract from tlie massive feeling which should be aimed at 
in representing the rise of a powerful neck from a well- 
developed thorax. 




I'ifJ. 187- Shows form of neck with shoulder 
depressed. 



Action of Sterno-mastoid 



373 



In regard to the action of the sterno-mastoid muscles — 
when one muscle contracts, the head is inclined to the same 
side, whilst the face is directed towards the opposite side. 
Concerning the combined action of the two muscles, there 
is much contradiction in the various textbooks : some assert 
that the muscles bend forward the head and neck, whilst 
others state that the muscles act as extensors of the head ; 
the truth appears to lie between the two statements. Their 
united action seems to be 
the bending forward of the 
neck on the thorax com- 
bined with the extension 
of the head upon the bent 
neck. In other words, they 
are in action when the 
neck is thrust forwards 
and the face upturned. 

Overlying the structures 
of the neck which have just 
been described is a dense 
layer of fascia called the -' 
deep cervical fascia. This 
invests not only the entire 
neck in a fibrous sheath, 
but also furnishes prolonga- 
tions from its deep surface 
which form compartments 
for the lodgement of these various structures. A detailed 
account of this fascia is needless, but the student would do 
well to remember the restraining influence which it exercises 
on the structures which lie beneath it. It is between this 
fibrous investment and the skin of the neck that the super- 
ficial fat which constitutes what is called the superficial 
cervical fascia lies. Here we have to study a muscle called 
the platysma myoides^ which is a survival in man of a muscle 




Fig. 1 88. Shows form of neck with 
shoulder raised. 



374 The Platysma 

which commonly occurs in many animals. Any one who has 
watched a fly settle on a horse's back has seen that the latter 
has the power of rippling or wrinkling its skin in a remark- 
able manner. The muscle which we are now describing 
belongs to the same class. Its development varies very 
much in diflferent individuals. Some people, too, appear to 
have much more control over its contraction than others. 

The lilatysma, which forms a thin muscular sheet, arises 
below from the fascia covering the great pectoral, the 
deltoid, and the trapezius : its fibres are directed obliquely 
upwards and forwards to pass over the lower jaw-bone 
from the chin as far back as the angle : some of its fibres 
are attached to this bone, but others pass up to blend 
with the muscles which are connected with the lower 
lip and angle of the mouth (see PL, p. 410, l). Under 
ordinary conditions there are no indications of the presence 
of this muscle, though in old people in whom the fat 
has disappeared it may be often recognized, as it forms 
the dewlap-like folds which hang beneath the chin. The 
action of the muscle is best displayed in the expressions 
of Iright and terror, wherein it draws down the angle of 
the mouth and wrinkles the skin of the neck transversely ; 
at the same time it appears to increase the transverse 
diameter of the root of the neck in front by flattening the 
surface forms over and above the collar-bone. 

Of other structures which lie in the superficial fascia 
we are concerned only with the veins. To avoid repetition 
the student is referred to the remarks already made on this 
subject at the end of last chapter (p. 357). The vein which 
IS most apparent is the external jiujiilar. This is well 
»oen ill the kjwer part of the right side of the neck of the 
Fighting (iladiator. It runs down the side of the neck, 
from the region beliind tho angle of the jaw to a point 
aUve the collar-hone and just external to the origin of the 
»tonio-iiia.stoid. Usually the vein of one side of the neck is 



Contours of the Neck 375 

mucli larger than that of the opposite. The superficial veins 
become distended with blood when the contraction of the 
muscles of the head and neck is prolonged and violent. 
They also become prominent under the influence of excite- 
ment. In the expression of rage and passion they are more 
or less engorged. Under all circumstances due care and 
restraint must be exercised in their representation. As 
indicated by colour, they are of service in imparting a 
feeling of delicacy to the skin. 

Having described in some detail the structures which 
determine the contours of the neck, we may pass on to 
consider the form of the neck as a whole. 

The neck is rounder in front than behind. The flattened 
surface of the back of the trunk is carried up on to the back 
of the neck without any interruption in the surface contours. 
In front, the rounded form of the root of the neck appears 
implanted on the breast between the shoulders, the modelling 
of which is distinct and separate from that of the neck. 
The spring of the neck from the shoulders on either side is 
very much higher than its root in the middle line in front, 
where the pit of the neck corresponds to the upper edge of 
the breast-bone. If the figure be viewed in profile, the pit 
of the neck is seen to lie on a very much lower level than 
the surface projection formed by the spine of the seventh 
cervical vertebra, which marks the inferior limit of the 
neck posteriorly. This is due to the oblique position of 
the first pair of ribs, which, with the breast-bone, form the 
boundaries of the inlet or superior aperture of the thorax. 
The effect of this obliquity is that the upper end of the 
breast-bone lies on a level with the second or third dorsal 
vertebra, hence it follows that the root of the neck appears 
to spring obliquely from the upper end of the thorax. This 
circumstance explains why in profile the front of the neck 
appears longer than the back. 

There is considerable variation in the length of the neck 



376 Length of Neck 

in different individuals. This is more apparent than real, 
and is not due to any marked difference in the length 
of the cervical portion of the back-bone, for observations 
prove that the back-bone is of all other parts of the 
skeleton the least liable to variations in its length. The 
length of the neck depends largely on the elevation of the 
shoulders. A long neck is associated with sloping shoulders, 
while broad and square shoulders are the concomitants of 
a short neck. The position of the shoulder-girdle depends 
to some extent on the development of the muscles which 
are connected with it, as well as on the form of the thorax, 
as has been already explained (p. 10 1). The sloping shoulder 
coincides with a collar-bone which slants outv/ards and 
downwards, whilst in the square-shouldered the outer end 
of the clavicle lies on a higher level than the sternal 
end. The muscular development of a person with sloping 
shoulders is usually poor ; hence the muscles of the neck are 
not so bulky: this reduces the width of the neck and tends to 
exaggerate the appearance of length. The broad and square- 
shouldered are commonly persons of powerful physique ; 
their muscles are usually strongly developed, and increase' 
thereby the width of the neck. This increase in the width 
of the neck detracts from its appearance of length. 

Much depends, as has been said, upon the quantity of 
subcutaneous fat which is here distributed. In women 
of a robust and healthy type the modelling of the neck is 
full and round, and only in exceptional actions are there 
indications of the superficial muscles. The fat, which is 
oftc5n present in considerable quantity, imparts a width 
to the neck which does away with any appearance of undue 
lon^th. In such the neck is often crossed in front by one 
or two (lf.li(iate cutaneous folds. This type is associated 
with a full and well-developed bust and shoulders. 

Another type is that in which we meet with the long and 
•wan-liko neck. This form occurs in women of a sparer habit 



Movements of Neck 



Zll 



with narrower chests and more sloping shoulders. The 
forms themselves may be very beautiful, but hardly convey 
that feeling of rude health which is so characteristic of 
the * former type. Here the slightness of the forms conveys 
a feeling of delicacy associated rather with a highly sensitive 
and nervous temperament. Owing to the less abundant 
layer of superficial fat we are in them more liable to have 
surface indications of the superficial structures. 




Fig. 189. Shows the hollow above the collar-loone when the shoulders 
are raised and the head bent forward. 



The neck undergoes very considerable modifications in 
its form according to its position. The movements of the 
head on the neck have been already referred to at the 
beginning of this chapter. As a matter of fact these move- 
ments are usually associated with corresponding movements 
of the neck. Thus when the head is bent forward the neck 
moves forward with it. A backward movement of the head 
is usually accompanied by extension of the neck. In like 



378 



Movements of Neck 



manner, tlie movements of lateral inclination and rotation 
of the head and neck are usually combined. The reader 
must not suppose that these movements may not be dis- 
associated. We can extend the head when the neck is bent, 
and we can flex the head on the extended neck, but these 
actions are unusual and constrained. 

Inflexion of the head and neck the hollow curve of the 

back of the neck dis- 
appears and is replaced by 
a convex outline, which, is 
an upward and forward 
continuation of the curve 
of the dorsal region of the 
back. The spine of the 
seventh cervical vertebra 
•becomes more prominent, 
and the spines of the upper 
two or three dorsal verte- 
brae can usually be recog- 
nized. The outline of the 
front of the neck is con- 
cealed by the fact that the 
chin comes into contact 
with the upper end of the 
breast-bone. A series of 
transverse folds cross the 
neck in front, the most 
pronounced corresponding to the surface of the skin imme- 
diately beneath the border of the lower jaw. The inner end 
of the collar-bone is emphasized, and the slight hollow which 
lies between tlio angle of the jaw and the anterior border of 
the stemo-niastoid is obliterated by the approximation of 
these two structures. The anterior border of the trapezius 
can usually be recognized passing from the occiput to the 
outer third of the collar-bone (Fig. 190). 




^I(i 190. Shows the form of the neck 
in flexion. 



Movements of Neck 



379 



When the head and neck are thrown back or extended, 
the angle formed by the structures underlying the lower 
jaw and the outline of the front of the neck is opened out. 
The hyoid bone, as we have seen, corresponds almost pre- 
cisely to this angle. The interval between the hyoid bone 
and the upper end of the breast-bone is increased, so that 
the outline between these two points is lengthened and the 
skin stretched over the sub- 
jacent structures. In the 
male the outline of the 
cartilages of the larynx is 
rendered distinct ; in the 
female, owing to the greater 
quantity of fat and the slighter 
development of these struc- 
tures, the outline describes a 
uniform forward curve from 
the pit of the neck to the 
angle where it sweeps for- 
ward to the chin (Fig. 191). 
In correspondence with this 
the back of the head or occiput 
is brought nearer to the 
prominence caused by the 
seventh cervical spine. The 
outline of the back of the neck 
is shortened and rendered 
more concave, and the skin is thrown into thick transverse 
folds, the skin of the back of the neck being much thicker 
and tougher than that of the front. The neck is somewhat 
increased in its transverse diameter by the outward thrust of 
the muscles, and, owing to the stretching of the skin over 
the lower jaw, the outline of that bone becomes more distinct, 
and the hollow between its angle and the anterior border of 
the sterno-mastoid is more pronounced. The lower attach- 




FiG. 191. Shows the form of the 
neck in extension. 



38o 



Movements of Neck 



ments of the sterno-mastoids are rendered tense, and tlie pit 
of the neck becomes sharply defined (Fig. 191). 

"Whilst the collar-bone is easily recognized by the stretch- 
ing of the skin over it, the hollow above it corresponding to 
the interval between the sterno-mastoid and trapezius 
becomes obliterated. A fullness appears over the back and 
upper part of the shoulder, owing to the relaxed fibres of 

the anterior part of 
the trapezius. 

When the head is 
turned towards the 
shoulder the skin of 
the side of the neck 
from which the head 
is turned is tense and 
stretched, whilst that 
on the side towards 
which the head is 
directed is obliquely 
wrinkled. The sur- 
face form of the side 
of the neck from 
which the head is 
turned is full and 

Fin. 192. Showsthe relation of the sterno- I'ound; the anterior 
n.a«toid to the surface when the head is border of the sterno- 
turned towards the shoulder. 

mastoid muscle is out- 

Htandiiig, tiiough its clavicular attachment is less marked. 

1 he skill as it is stretched over the collar-bone emphasizes 

tliut structure, and the hollow above it is effaced to a 

great oxtent, though the border of the trapezius may be 

frequently recognized. The posterior belly of the omo- 

liyoid us it crosses the lower part of the interval between 

tlie traj)ezius iui.l sterno-mastoid is stretched, and often 

forms a surilico (ilevation when there is little subcutaneous 








Movements of Neck 



381 



fat. On the side towards which, the head is turned the 
hollow above the collar-bone is deepened, but the outline 
of the superficial muscles is concealed by the wrinkled skin. 
A deep cutaneous fold defines the angle of the jaw and runs 
up behind the ear, marking the interval between the jaw- 
bone and the anterior border of the upper part of the sterno- 
mastoid (Pis., pp. 72, 86, 132, 152). 

By the rotation 
of the head and 
neck the structures 
which lie in the 
middle line of the 
neck are dragged 
obliquely towards 
the side to which 
the head is turned, 
and in the male, as 
also to a slight ex- 
tent in the female, 
the form of the 
laryngeal cartilages 
is apparent (Pis., 
pp. 86, 132, 308). 

In the lateral move- 
ments, in which the ^ig. 193. Shows the relation of the sterno- 
liead is inclined to- mastoid to the surface when the head is bent 

T ,T 111 to the side. 
wards the shoulder, 

the skin over the neck on the side towards which it 
is bent is wrinkled : the best marked of these folds corre- 
sponds to the spring of the neck, and curves round the 
root of the neck from the inner end of the collar-bone 
upwards and backwards across the middle of the anterior 
border of the trapezius, whilst another follows more or less 
accurately the anterior border of the sterno-mastoid, passing 
up between it and the angle of the lower jaw to reach the 




382 



Slemo-mastoid. Trnpezins. Plalysiiia. .Acromion process of scatmla. _.L/avu. 

/ / ,' ■■' ..-••■■' ■■ Delia, 



5 lerno-masloij. 

Trn/)t:iMS 

Pit 0/ tuck. 

Clavulf... 

Acromion process 

Pecloralis ma/or. 
clavuMLtr Jibrfs 
iternal fibrti 

/W/.v-/ 

Pit of slomatk 

Redm obdomiiiis. 

I.tnfiu tramvcrsae 
Iliac erfst 

An! i up iliac spine. . 
Tru/fi. fliiUr head. 
Trtcfp,_ ,„„fr l,f„^ 
Pic eft (ubili 
Bratkialis aniuus. 
Tensor /asciite femorii 
llio-ptoai ■ 
Pettintui 
Adductor loiipi:. 
I'ron.ilor radii tern 
Hu 1^1 1,1 1 fa sua 
Ext tarp rod long 
Supinator longus. 
FUx earpt radialis. ' 
(jraeiht. 

I' *t carprad brn ' 
/-.Mltniort of thumb - 
P Mt lom dieilorum 
Annular ligament 
yailut inlernui. 
Pafr/I., 

Internal ttmJyle 
l.igamentum paUllat. 
Sartariui 
lite tihal band 
Permifut Inngui 
(»ti/rtrnrmiui. 
inner ktaJ 

Tt^lii antuni 

Jthta, lubruttfn 
emu tmr/att 

I tltnt^r I'-gtit 
digitofum ptdii 
llnUmditpedn 
L^g extemtar •/ grmi 

l^lernal malMu, (tAm\.. 
^'^'"'•f»«nt,/ambl. 



Pecloralis mnjor, 
clavicular Jibf- 

..Triceps, outer /tea 
.Brachialis anticu 

_.. Triceps Iciide- 

... Biceps cubii 

. Latissimus don 

_IJigitii lions 0/ 
serralus mapm 

Ext. inter mus. septun 

Supinator longu 

Ext. carp. rod. Ion 

Digilalions of external obliqu 
■ E.vleitsor communis dig, 
Ext. carpi radialis brcvioi 

Extensors 0/ ihum 

Extensor carfi iilnari 

Annular ligamen 

Ant sup. iliac stin 

Gluteus inediu. 

■Aponeurosis of 

external obligm 

Poiipart's ligamen 

Tensor fasciae femori 

"". Ilio-psooi. 

-Pectineu 

■Adductor longu 
Gracilii 




Sartoriu 

Rectus /emorL 

■Vastus internu. 

Band 0/ Rielin 
Vastus externm 

PatelU 



Internal condyi 

Ea. 

Ligamentum patella, 

Sartoriu 

Tubercle of tibi 
■ Gastrocnemius, inner heai 

•■ 7 ibialis anticu 

I ibia, subcutaneous surfac 



-Soleu 

Jxt longu s digitoruiH pedt 

Elcx.longus digilorum pedi 

Ten do Ac hi III 

extensor of great to 

'iir ligiiiiient ofanii 

nal niallenlus {tibia 



Neck and Shoulder 383 

back of the ear. On tlie side from which, the head is 
inclined the sterno-pnastoid is distinct!}^ seen, its origin 
from the collar-bone being especially evident. Here too the 
collar-bone is bronght more or less into prominence by 
the stretching of the skin over it, and the attachment of the 
trapezius to that bone is usually easily recognized. A surface 
elevation dependent on the posterior belty of the omo-hyoid , 
may also be noticed. These forms will of course be very 
much modified if the shoulder from which the head is in- 
clined is elevated at the same time (Fig. 193, and PI., p. 72). 

It only remains to be said in this connexion that the 
sweep of the fibres of the trapezius, as they pass from 
the occiput and the middle line of the back of the neck 
downwards and outwards towards the outer end of the 
collar-bone and upper border of the acromion ^process of 
the shoulder-blade, plays an important part in linking 
together the shoulder with the neck. Their presence deter- 
mines the outline which passes from the side of the root of 
the neck to the shoulders. The direction of this outline 
will vary with the position of the shoulder-girdle. It has 
a downward slope when the shoulder is depressed, but 
when the limb is elevated or the girdle raised it becomes 
more nearly horizontal (PL, p. 152). 

The influence of the fibres of the platysma must not be 
overlooked, but it is only exceptionally and in strained 
action that the contraction of this muscle masks the details 
of the underlying structures. 



CHAPTER XIII 

THE HEAD, FACE, AND EXPEESSION 

The sJcull is the bony framework of the head. It is 
conveniently divided into two parts, one of which envelops 
and protects the great nervous centre, the brain, while the 
other forms a series of chambers for the lodgement of 
some of the organs of special sense, viz. the globe of the 
eye, the nose, and the tongue. The former is called the 
cranial box or calvaria ; the latter is known as the skeleton 
of the face. All the bones forming these several parts 
are immovably united to one another, with the exception of 
the mandible or lower jaw, which articulates by means 
of a movable joint with a hollow fossa in front of the 
ear on the under surface of the temporal bone. 

As the brain in man is larger in proportion to the rest 
of his body than in any other mammal, the bony case 
which surrounds it necessarily attains a great size. On 
the other hand, as was pointed out in Chapter I, a corre- 
sponding reduction Las taken place in the size and projection 
of the facial part of the skull; the jaws are no longer 
necessary for offensive or defensive purposes, nor are 
they so powerful, for man almost without exception 
prf'parf's and softens his food by cooking. The sense of 
Hmcll IS not nearly so keen in man as in many animals, 
in wliom it serves to protect them from their enemies 
and assists them in obtaining their food. This has led to 
a cornrsponding reduction in the size of the nose in 
man. In animals the nose and jaws form a muzzle or 
»nout, which projects in front of that part of the skull 



The Skull 



385 



which, contains the brain, whilst in man the large cranial 
box overtops the greatly reduced facial skeleton in place 
of lying only behind it, as in the lower animals. 

These two parts of the skull can be conveniently defined 
in the living by drawing a line from the root of the nose 




Fig. 194 

a. Frontal bone. h. Parietal bone. 

c. Occipital bone. 

d. Temporal bone. 

e. Nasal bone. 

f. Upper jaw-bone (superior maxilla). 

g. Cheek or malar bone. 

h. Mandible or lower jaw (inferior 
maxilla). 



Male skull. Side view. 



i. An^le of lower jaw. 
j. Ramus of lower jaw. 
k. Condyle of jaw. 
I. Zygomatic arch. 
777. Mastoid process of temporal bone. 
n. External occipital protuberance. 
0. Coronoid process of lower jaw. 



to the orifice of the ear, and thence backwards to the point 
where the neck unites with the posterior part of the 
head in the middle line. There, a rounded knob of bone 
can usually be felt : it is called the external ^protuberance 
of the occipital hone. 

The part of the skull above this line is for the lodgement 



TnOMSOH 



c c 



386 



The Skull 



of the brain', that below and in front of the line which 
stretches between the root of the nose and the ear belongs 
to the face. 

The cranial box is built up of expanded plates of bone : 
these present a smooth and rounded appearance where they 

form the dome-like roof and 
sides of the head, and im- 
part to it its characteristic 
shape. The form and size of 
the head vary very much in 
different individuals, a cir- 
cumstance which usually en- 
ables us with certainty to 
recognize our own hats. 

The under surface of this 
bony box is called the hase 
of the skull. In front, it is 
united with the bones of the 
face. Behind, it is rough and 
irregular and pierced by 
many holes. Here it affords 
attachment to a great many 
muscles, which control the 
movements of the head. By 
a large hole, called the fora- 
men magnum^ placed imme- 
diately over the canal in the 
vertebral column for the 
lodgement of the spinal cord, 
it allows that nervous structure to pass upwards and become 
connected with the brain. 

We are in no wise concerned with these details, nor is 
it necessary that we should further discuss the manner in 
\\\\\v\i the head articulates with the top of the vertebral 
column. This was described in the last chapter (p. 360). 





% 




Fio. 195. Male skull. Front view, 

a. Frontal bone. 
/*. Pariotal Ixjnes. 

d. Temporal bones. 

e. NoKiil bones. 

/ Upper jaw-bones. 
g. Malar or chook-bonos. 
h. Mandible or lowor jaw. 
i. Arif^lcH of lower jaw. 
3. Ilaiiii of lower jaw. 
' ZyKrimntic arches. 
m. "VLiuiUt'ui processes of temporal bones. 



Bones of the Skull 387 

The bones of the cranial vault, as we pass from before 
backwards, are named the frontal, which forms the fore- 
head ; the two parietals, one on either side, which con- 
stitute the top and part of the sides; and the occipital 
bone, which forms the back of the head. The side of the 
cranium in front, above, and "behind the ear is made up 
of the temporal bone. In addition a portion of the sphenoid 
fills up the interval between the temporal bone posteriorly 
and the frontal anteriorly on either side. 

-It is unnecessary to describe these in detail, for it 
is by their union with each other that they mould 
the form of the head. There are but slight indications 
of their lines of union in the living, and the hairy 
scalp further conceals any evidence of their outlines. 

They are united by a series of interlocking teeth-like 
projections, and the joints so formed are called sutures. 
In Chapter II the advantage of this arrangement was 
pointed out. The bones are by this means immovably united, 
at the same time that growth by expansion is rendered 
possible. In the aged, after all growth has ceased, these 
sutures frequently disappear, and the bones can no longer 
be separated from one another, as they have become fused 
together by osseous union. 

The structure of these bones requires some explanation. 
They are composed of a dense inner and outer layer, 
the interval between which is formed of softer and more 
spongy osseous tissue, called the diploe. In some situations 
this diploe is liable. to disappear at certain periods of life. 
Spaces are thus formed between the inner and outer 
hard layers. Through their connexion with the respiratory 
passages these spaces contain air, and are hence called 
air sinuses. The growth of these air sinuses takes place 
in the earlier periods of life, but some of them are 
strikingly developed at that age when youth merges 
into manhood. One of these sinuses has a special interest 

c c 2 



o88 Frontal Stmts 

for us, as it leads to very considerable modifications in 
the surface form of the bone. The frontal bone, as it 
moulds the forehead, can be felt underneath the eyebrows, 
forming the arches over the cavities in wbich the eyes 
are lodged. In this situation it is hollow, and contains 
an air sinus called the frontal sinus. This space is not 
developed in childhood, and only to a slight extent in 
youth. In man it attains its maximum development 
and imparts to the bone underlying the eyebrows a marked 
fullness and prominence. In this respect man differs from 
woman, for in the latter the sinus is much smaller, resem- 
bling rather the condition met with, in childhood. This 
explains why a woman's forehead is flatter and smoother 
than a man's, and accounts for the persistence in her of 
the juvenile type. 

The bones of the vault of the cranium ossify in a peculiar 
way : they are what are termed membrane-bones. In the 
early stages of growth the bone appears in the form of 
a localized earthy deposit in the membrane which is subse- 
quently to become ossified: from this centre the ossifying 
particles spread until the membrane has become converted 
into a plate of bone. These 'centres of ossification ' are 
roadily recognized in the child ; they constitute the ' bumps ' 
whicli are so easily seen and felt in certain situations. 
The most noticeable of these are the frontal and the parietal 
emtnences; the former cause the projection of the upper 
part of the forehead on either side, whilst the latter can 
bo roiidily folt at some little distance above the ears. 
The fullness imparted to the child's forehead by those 
frontal contrns of ossification is maintained through- 
out hfo, though not in such a pronounced form, for in man, 
owing to the development of the frontal sinuses, the brows 
becomo more projecting, thus causing the forehead to slope 
more, and so reducing the appearance of prominence in the 
n-gion of the frontal eminences. In women, owing to 



Cranium 



389 



the feebler projection of the brow ridges, the forehead retains 
its vertical appearance and the frontal bosses seem more 
pronounced. In this respect again the female resembles 
the child. 

The relative proportion of the brain-case to the face 
varies much at different periods of growth. Apart altogether 
from the proportions of the head in relation to the rest of 
the body, the most casual observer must have noticed that 
in the child the part of the skull which contains the brain 
is relatively much larger as compared with the face than 




Fig. 196. Skull of adult showing Fig. 197. Skull of child showing 
proportion of face to brain- case. proportion of face to brain-case. 



what we see in the adult. Growth takes place in both 
these parts concurrently, though to a greater extent in 
the structures of the face than in the cranial box, else the 
relative proportions met with in the adult could not be 
attained. 

The size of the cranial box is some index of the 
development of the brain, since a large brain necessarily 
requires a large covering. The size of the brain may, 
with certain reservations, be regarded as an indication 
of the development of the intellectual faculties. Though 
it by no means follows that a man with a big head is 



390 Size of Head 

a i)Iiilosoplier, yet, speaking generally, it may be stated 
that the more civilized the race the larger the brain, 
and consequently the bigger the head. 

Since women as a rule are smaller than men, so we find 
that their brains are smaller than men's; not only are 
they absolutely less, but also relatively so in proportion 
to the bulk of the bod}^ Curiously enough, this dispro- 
portion between the sexes is less marked in savage than in 
civilized races; in the latter perhaps the difference has 
been emphasized by the greater facilities afforded for the 
education of the intellectual faculties in the male. Cor- 
related with these facts is the size of the head, which 
in woman should be small and shapely, though this is 
often concealed by the luxuriance of the hair. The fashion 
of wearing the hair naturally modifies the appearance of 
the head : travellers have frequently been misled thereby, 
describing races as big-headed in which in reality the skulls 
were of small size. 

Whilst willing to admit that a well-shaped head is 
some guarantee of high mental and moral attainments, 
it must be pointed out that the detailed mapping out 
of the faculties on the surface of the skull is not based 
on, or supported by, any scientific facts. 

As has been said, the face is proportionately small in the 
young child. As yet the air sinuses in the bones have not been 
fully developed. These air sinuses are all accessory to the 
respiratory tract, with which they communicate. They act 
apparently as resonators, and influence thereby the character 
of the voice. Many of them are connected with the nose, 
and the reader will at once appreciate their effect on the 
vuico if ho notes the changes which take place in its 
quality wh.Mi one is suffering from a severe cold in the 
hcud. 

The most imj)ortunt of these sinuses in connexion with 
the face is that Ibuiid uithin the upper jaw, a bone, which 



Bones of Face 391 

tiiougli apparently solid, displays on section a large cavity 
in its interior. Besides the function above ascribed to 
these sinuses, it will be evident that by substituting hollow 
bones for solid ones the weight of this part of the skull is 
very much diminished. 

Among the most important of the bones of the face as 
determinants of form are the cheek or malar bones. These 
impart the width to the upper part of the face. If the 
finger be placed upon the brows, and the outline of the orbits 
be traced beneath the skin, these bones may be felt as they 
form the margin of these hollows to the outer and lower side, 
lying in this position between the outer parts of the frontal 
bone above and the upper jaw-bones below. Wide of the 
orbit the malar bones form the prominence of the cheeks. 
Posteriorly they can be felt to be supported by an arch of bone 
which can be readily traced back to the region in front of 
the ear. This is called the zygomatic arch, and is in part 
made up of a backward process of the cheek-bone and 
a forward projection of the temporal bone. Beneath this 
arch, when the skull is stripped of its fleshy parts, there 
is a hollow extending up on either side of the head. This 
is called the temporal fossa, and in it is lodged a large muscle 
called the temporal muscle. The reader may satisfy himself 
as to the presence of this muscle by placing his fingers 
above the zygomatic arch and then opening and closing 
the mouth alternately. The fibres of the muscle will then 
be felt contracting, for they are inserted into the lower jaw 
and help to move that bone (Figs. 194, 195, 200). 

The zygomatic arches therefore act as buttresses to the 
cheek-bones, at the same time that they allow the fibres 
of the temporal muscle to pass beneath them to be inserted 
into the lower jaw. 

• The character of the face largely depends on the cheek- 
bones. It is to these that the Mongolian and Tartar races owe 
their characteristic flatness of face ; whilst they impart to the 



392 The Facial Angle 

Australian aborigines their remarkable breadth of features. 
The prominence of the cheek-bones, apart from these racial 
characteristics, depends largely upon the fullness of the 
tissues of the cheek. When, from absence of fat or wasting 
of the tissues, the cheek loses its roundness, the form of the 
malar bones becomes more easily recognized. Under these 
circumstances we describe a person as having high cheek- 
bones. This prominence is more apparent than real, and 
depends, as has been said, on the wasting of the surrounding 
tissues rather than on any undue projection of the bone 
itself In old age they become prominent by the sinking of 
the cheeks beneath them. 

As has been said, one of the characteristic features of 
man's skull is the absence of a muzzle : though this is the 
case, it is true that minor degrees of projection of the upper 
together with the lower jaw are met with. These variations 
in the position of the bones lead to very characteristic dif- 
ferences in the appearance of the features. The student 
may best realize this by contrasting the two extremes: 
viz. the ideal type represented in the antique, and that 
characteristic of the negro races. In the one the outline 
of the face is more or less vertical ; in the other it slopes 
forward. 

A Dutch anatomist named Camper was the first to draw 
attcintion to this difference and record it by a scientific 
method. The projection of the face caii be expressed by 
what IS termed tha facial angle. A base line is taken which 
I){Lssf's across the face, cutting the orifice of the ear posteriorly, 
and lying on a level with the border of the septum of the nose 
in front ; on this another straight line is drawn which touches 
the most prominent part of the forehead above, and the 
ant4.rior surface of the upper incisor teeth or the front of 
the uppor lip bolow ; the angle formed by the intersection 
of tho two lines, marked in Uie accompanying diagrams, is 
the facial angle (Figs. 19B, igg, c e b). 



The Facial Angle 



393 



In order to measure this angle on the living, different 
forms of apparatus are used, but the method described 
above, if applied to a profile outline of the head, will enable 
the student to recognize the variations met with. 

The angle ranges from 62° to 85°. These are the extremes. 
The former figure indicates a very marked projection, the 
latter a more vertical outline. Commonly the angle 
measures from 70° to 80° ; the white races being characterized 
by a facial angle of from 75° to 80°, the yellow by 
an angle which ranges from 70° to 75°, whilst the negroid 





Fig. 198. Head of a European. 



Fig. 199. Head of a Negro. 



The facial angle c e & is formed by the two lines a h and c d. In the negro 
the angle c e & is smaller than in the European, owing to the greater projection of 
the jaws. 

races display a projection of the lower part of the face 
which often causes the facial angle to fall below 70°. 
In other words, the European races have more or less 
straight faces ; the yellow, slightly sloping faces ; and the 
black, markedly projecting faces. In the latter this appear- 
ance is further emphasized by the presence of a broad and 
flattened nose, and thick and everted lips. 

In the more highly civilized races, as we have seen, the 
face is much straighter, and this may account for the ideal 
forms represented in the antique, in which no doubt 
a sense of dignity is imparted to the features by the 



394 The Lower Jaw 

undue emphasis of this condition. In some of these 
the facial angle exceeds a right angle, a condition not 
met with in man under normal circumstances. Subjected 
to these tests many of the types represented in the 
antique are impossible, yet in spite of all such criticism 
they still remain the embodiment of all that is great 
and noble in art. 

Another bone of much importance in the modelling 
of the face is the lower jaw. This is divided into two 
lateral halves, united together in the middle line in front, 
each half consisting of a body, an angle, and a ramus. The 
bodij of the jaw is that part which forms the arch which 
supports the lower teeth ; in front it determines the pro- 
jection of the chin, and its lower border can easily be traced 
beneath the skin backwards to a point a little in front of 
the ear. Here its lower border turns suddenly upwards, 
forming the angle, and becomes continuous with the 
posterior border of the ramus. The upper end of the rami, 
for there is one on each side, supports two processes. The 
hinder of these, which is called the condyle of the jaw, 
is furnished with a surface by means of which it articulates 
with the temporal bone in front of the ear, in a way which 
will bo described below. Separated from this by a notch 
called the coronoid notch, and lying in front of it, is a 
pointed process called the coronoid process. This process, 
when the jaws are closed, passes up beneath the zygomatic 
arch, and into it the fibres of the temporal muscle, pre- 
viously referred to, are inserted (Figs. 194, 195, 200). 

The temporo-maxillary articulation is a joint of peculiar 
construction. In place of the cartilage-covered condyle of 
the lower jaw, coming in contact with the articular hollow 
on the under surface of the temporal bone, a pad of cartilage, 
callod a meniscus, intervenes between them; the upper 
•urfaco of this is adapted to fit on to the articular surface 
of tho t<;mporal bone, whilst its lower aspect is moulded 



The Mas set er 395 

to receive the rounded condyle. These two joints are 
distinct and permit of different though associated move- 
ments. Thus a gliding movement takes place between 
the meniscus and the temporal bone, whilst a hinge-like 
movement occurs between the meniscus and the condyle. 
As already stated, the two movements mentioned above are 
intimately associated, as may be demonstrated by placing 
the finger over the joint and opening the mouth, when not 
only will the jaw be felt to swing, but the prominence 
caused by the condyle will be observed to advance forwards 
towards the cheek. Besides the movements of opening and 
closing the jaws, we can also move the lower jaw from side 
to side as in grinding the food. Further, we have the 
power of protruding or retracting the lower jaw, all of 
which movements occur at this articulation. 

Connecting the lower border of the zygomatic arch 
with the outer surface of the jaw-bone, corresponding 
to the angle, is a powerful muscle called the masseter. 
Of quadrilateral form, it overlies the ramus of the jaw, 
and so conceals its outline, except behind, where the 
posterior border of the ramus can readily be felt as it 
passes up in front of the ear. The masseter thus corre- 
sponds to the hinder and lower part of the cheek, the 
fullness of which in this situation is due to the presence 
of this muscle. The reader may satisfy himself as to 
the correctness of this statement by placing his fingers 
on his cheeks a little in front of and above the angle of 
the jaw; then on firmly closing the jaws he will feel the 
hardening caused by the contraction of the muscles. These 
two muscles, the temporal and the masseter, as they arise 
from fixed attachments on the side of the skull, elevate 
the inferior maxilla and so close the jaws. They are much 
concerned in the movements of chewing, and are hence 
classed among the muscles of mastication. 

The size of the lower jaw varies much, being small in 



39^ 



Form of Lower Jaw 



infancy, large in adult life, and again reduced in old age. 
But coincident with these changes in size there are also 
alterations in shape. If the jaw of a child be examined, the 
angle formed by the ramus with the body is seen to be 
much more open than that displayed by the adult, in whom 
it more nearly approaches a right angle. With advancing 
years the angle again alters, and becomes more like that 
seen in infancy. The growth and eruption of the teeth 




Kio. 200. Side of the skull, showing the position of the temporal and 

masseter muscles. 



o. Condyle of lower jaw. 

b. IkxJy (if lower juw. 

c. Miliar or check bona 
■*. ICaiMsUr muscle 



0. External occipital protuberance. 
t. Temporal muscle. 
X. Mastoid process of temporal bone. 
z. Zygomatic arch. 



have much to do with the form of the jaw. Whilst the 
child dorivos its nourishment from the mother the body of 
tho jaw remains small ; but when nature provides it with 
t«eth to chew its own food the jaw alters its shape. It is 
only aft^jr tho permanent teeth have succeeded the milk- 
t^^eth that tho lower jaw attains its full development. In 
hit^jr hfo, when tho natural process of decay, or it may be 
<liHca.sc. leads to the loss of the teeth, a shrinkage and 



The Teeth 



397 



atrophy of the bone take 
place, which bring about the 
alterations in form charac- 
teristic of old age. 

These variations in the 
shape and size of the jaw are 
associated with alterations 
in the surface forms, and 
account for the nut-cracker 
appearance imparted to the 
faces of old people in whom 
the jaws are toothless. The 
lips and cheeks, no longer 
supported by the teeth, are 
thin and wasted and form 
loose and wrinkled hollows. 

The size of the teeth varies 
in different individuals. The 
lower races of man as a rule 
have larger teeth than the 
more highly civilized. This 
is no doubt accounted for by 
the fact that the higher races 
pay more attention to the 
preparation of their food by 
cooking, &c. Large teeth 
necessarily require large jaws, 
and we can thus account for 
the massive lower jaws met 
with in many savages. Too 
big a jaw imparts a brutal 
appearance to the face, a 
feature which draughtsmen 
have often emphasized in re- 
presenting the criminal type. 




Fig. 20I. Infant. 




Fig. 202. Adult. 




Fig. 203. Old Age. 

Show the shape of the lower jaw and 
its influence on the surface form in 
infancy (Fig. 201), in the adult (Fig. 
202), in old age (Fig. 203). 



398 The Orbits 

The chin is a very characteristic feature of man's face ; 
it depends on the forward projection of the central point 
of the lower jaw. It presents a variety of forms: it should 
be full, prominent, and somewhat square in the male, in 
contrast with the more pointed form which is so pleasant 
3 feature in women. Not unfrequently a depression or 
dimple overlies its centre, due to a muscle which is here 
attached to the skin and which helps to raise the tissues 
of the chin in certain expressions. This muscle is called 
the levator menti ; it takes its origin from the front 
of the lower jaw, beneath the lower lip (PL, p. 410, 
Fig. 2, c). The fullness of the chin is increased by the 
quantity of fat which underlies the skin. In cases where 
this is abundant the chin is circumscribed by a fold below 
which defines it from the fullness beneath the jaw. Not 
unfrequently the tissues here are so loaded with fat as to 
give rise to the appearance of double-chin. 

In some, owing to the feeble development of the lower 
jaw, the chin, instead of being prominent, recedes. This 
imparts a feeling of weakness to the whole face, in striking 
contrast to the look of strength and determination asso- 
ciated with a square jaw. 

The other parts of the skeleton of the face do not require 
much description, as their form is masked by the overlying 
tissues. 

The shape of the orbits or hollows in which the eyes are 
lodged varies considerably in different races. The most 
pronounced feature, and one which alters considerably the 
appearance of the face, is the overhang and projection of the 
brows. This, as has been said, depends on the presence of 
largi. irontal sinuses and corresponding brow ridges— a con- 
dition whicli leads to modifications in form of the lower part 
of tho forehead in the male as contrasted with the female. 

Thn form of tho nose depends on the shape and size of the 
nnml hours and the arrangement and form of the nasal 



Nose and Ear 399 

cartilages. In a skull in which the nasal cartilages have 
been destroyed, in the process of preparation, the form of 
the nasal aperture is like an inverted ace of hearts ; but 
on looking at a number of skulls of different races it will 
be seen that this opening varies considerably in appear- 
ance. In the negroid races it is broad and short, whilst 
in the European it is long and narrow. This corresponds 
with the form of the nose in the living. The negro has 
a broad flat nose, whilst in the white man the nose is long 
and thin. 

Differences in the form and projection of the nasal bones 
are associated with characteristic variations in the shape of 
the nose in the living. So also the moulding of the nasal 
cartilages plays an important part in this the most pro- 
minent feature of the face. The disposition of the nostrils 
and the form of the end of the nose depend on these struc- 
tures. The persistence of type in the arrangement of these 
parts is often remarkable, as exemplified in the characteristic 
nose of the Jewish race. 

The root of the nose is very variable. Formed as it is 
by the nasal bones, its outline depends on the shape and 
disposition of these bones. In some the root of the nose 
is depressed and clearly marked by a hollow from the 
ridge of the brows ; in others it is more projecting and 
carries down the outline of the forehead. 

Further description of this feature is unnecessary. A great 
variety of shapes are met with, but the student can now 
realize on what structures these modifications in form 
depend. 

The external auditory meatus marks the position of the 
ear on the skull. It is a canal leading into the interior 
of the temporal bone, placed between the articular hollow 
for the lower jaw-bone, in front, and the projecting process 
behind, called the mastoid process, to which the anterior 
fibres of the sterno-mastoid are attached. 



400 The Ear 

In front of this aperture the temporal portion of the zygo- 
matic arch springs. 

Implanted in and surrounding this orifice is a convoluted 
leaf of cartilage, which when covered by skin forms the 
shell-like ear. Connected with the cartilage below is 
a quantity of fatty tissue which forms the lobe of the ear. 
Great differences are seen in the shape and size of the ear. 
In women it should be small and not projecting, its delicacy 
being enhanced by its colour and the light and shade which 
its contours impart. In men it should not be unduly large, 
and should lie close to the side of the head. Unpleasant 
forms are due to irregularities in the folding of the car- 
tilage and a spreading out of its edge. The lobe too 
varies, in many being absent, whilst in others it is not 
free in front, but is tied down to the tissues of the 
check. Attempts have been made to identify these con- 
ditions with racial characteristics, but sufficient has been 
said to enable the student to judge for himself as to the 
forms most suitable for representation. Below and behind 
the ear, the hollow, which lies between the jaw in front 
and the anterior border of the sterno-mastoid behind, ends 
abruptly. 

Wo have hitherto confined our description to the bones, 
cartilapjcs, and some of the muscles which influence the 
surface form of the face ; but covering the front of these, 
and serving as a mask, is an investment of skin and fat and 
muRclos. It is to this that our attention must next be 
directed. 

It will bo well, in the first instance, to study the various 
oi)oning8 on the face. Of these there are five— the mouth, 
tho nostrils, and the openings between the eyelids. The 
orifice of tho oar is not included, as it lies on the side 
of tho head and has already been sufficiently described. 
All thoso openings are liable to modification in their 
form by tho action of the muscles which surround them. It 



The Month 401 

is largely to these alterations in shape that the expression 
of the emotions is due. 

The mouth, the largest and most important of these 
apertures from the point of view of expression, is the cleft 
between the lips ; it varies much in size and in the form 
of its boundaries. The lips should be fall and rounded, the 
red parts being clearly defined from the rest by a more or 
less prominent margin. The upper lip should project some- 
what, so as to throw part of the under lip in shadow. The 
form of the upper lip is often a feature of great beauty. 
From the angles of the mouth the red part of the upper lip 
should curve over so as to form an arch, the centre of which, 
however, is interrupted by a gentle groove which passes 
across its middle from the septum of the nose. As this 
groove joins the red edge of the lip it breaks the continuity 
of the curve and imparts to it that characteristic appearance 
which has been named "Cupid's bow'. It is just where this 
groove breaks the outline that the lip is most prominent. 
The upper lip varies considerably in length in different 
individuals, a short lip being regarded as one of the 
attributes of ideal beauty. The lower lip, though full, 
should not project as far forwards as the upper. Beneath 
its red part it should be recurved and separated by a broad 
depression from the prominence of the chin, thus tending to 
cast a shadow beneath, which helps to accentuate its curved 
outline. At the angles of the mouth the red parts of the 
lips are narrowed down to a line and tend to be inturned. 
The fullness of the tissues of the cheek here forms an angular 
depression which, thrown in shadow, breaks the otherwise 
abrupt union of the upper and lower edges. The modelling 
of these parts displays great subtilty of form and imparts 
a delicacy and finish to the curves of the lips. It is hardly 
necessary here to remind the reader of the many defects 
displayed in this feature. 

An undue length of the upper lip. as well as thinness or 

THOMSON D d 



402 The Eyes 

excessive fullness of the red parts of the lip, are characters 
which should be avoided in ideal conceptions, though doubt- 
less they have their value in the representation of more 
realistic types. The most remarkable feature about the 
mouth is its extreme mobility; this we will see hereafter is of 
th^ greatest value as a modifying influence in expression. 

The structures which determine the form of the nose 
have been already described. The form of the nostrils dis- 
plays many varieties, according to the shape of the nose. 
These openings are separated by the septum, which joins 
the upper lip at a point corresponding to its median -furrow ; 
on either side, the cartilages which form the alae of the 
nose overhang the nostrils. These cartilages are separated 
posteriorly from the fullness of the cheek by a curvilinear 
furrow. Their lower borders are more elevated than the 
lower border of the septum, so that in profile the septum 
determines the outline, and the aperture of the nostril 
is seen. The shadow thrown across the nostril by the 
overhanging ala is warm in tone, owing to the exposure of 
the highly vascular membrane which lines the interior 
of the opening. It is worth noting at present that the 
alao of the nose are slightly movable, and are to a certain 
extent under the control of the will. 

The size of the eyes depends on the extent of the surface 
of the globe exposed between the eyelids. This naturally 
varios with the length of the fissure between the lids, 
which on the statement of expert authority should form 
ono-fifth of the width of the head. The two apertures 
Bhoiild bo separated by a width equal to the length 
of one. 

With the eyes open, tho angles formed by the union of 
the upper and lower lids should lie on the same horizontal 
1'"". Deviations from this are not uncommon, the most 
remarkable being that in which the outer angles are raised, 
thus Riving the eye an oblique appearance. It is partly due 



i 



The Eyes 403 

to this obliquity that the eyes of the Chinese and Japanese 
owe their distinctive appearance. Another characteristic of 
these races is the condition known as ejpicanthus ; in this 
the inner angle of the eye is overhung by a fold of skin 
which passes downwards from the upper eyelid. This 
appearance is not unfrequently met with in European 
infants, though in them it usually disappears as the child 
grows up. 

The globe of the eye rests on a pad of fat within the orbit. 
Its movements are controlled by the action of six muscles 
which are attached to it. If the fat within the orbit be 
scant in amount, the eyes appear deep-set and sunken. 
When prominent the condition depends on the increase 
in the bulk of these supporting pads. 

The setting of the eyes is further affected by the pro- 
minence of the brows. When these overhang, the eyes 
appear deep-set. The orbital margin is only recognized 
as a surface form along the brows and towards the outer 
side. Below, the skin passes from the lower lid to the 
cheek without any indication being given on the surface 
of the lower margin of the orbit. 

Of the two eyelids, the upper is the longer and the 
more movable. The closing of the eye is effected by the 
descent of the upper eyelid, and not by the raising of 
the lower lid. The margin of the upper lid is more curved 
than that of the lower. Both margins are furnished with 
eyelashes, of which the upper are the longer. The margin 
of the upper lid is sufficiently thick to throw a shadow on 
the eyeball beneath it. Viewed from the front or side, the 
surface of this margin is not visible. The margin of the 
lower lid, thinner than that of the upper, is upturned, and, 
viewed from the front in ordinary positions, is clearly 
seen. From its colour and from the fact that, being a 
moist surface, it more readily catches the light it forms 
an element of much importance in the drawing of the eye. 

D d 2 



404 The Eyes 

The inner and outer, angles between the eyelids differ. 
The outer angle, or external canthus as it is called, is formed 
by the upward curve of the lower eyelid beneath a fold 
which is continuous with the margin of the upper lid. In- 
temall}^ the two eyelids do not directly unite with one 
another, but are separated by a small 3-shaped recess. Here 
are found the ducts which carry away the tears, and here 
also a small triangular-shaped vascular fold, which stretches 
across the angle between the lids, supplies the painter with 
opportunities of applying local colour. The red tint of this 
fold is carried inwards into the recess aforementioned. 
Passing inwards towards the root of the nose from the inner 
cavfhus, for about one-eighth of an inch, a prominent surface 
riflge can often be seen which is due to the presence of a 
little ligament called the tendo oculi, which unites the eye- 
lids with the inner wall of the orbit. 

When the eyes are closed, as in sleep, the form of the 
upper lid depends on the shape of the eyeball. This is not 
a simple sphere, but consists of part of a sphere of smaller 
diameter placed on the front of a larger one. It might be 
compared to a well-curved watch-glass placed on the surface 
of a cricket-ball. This more prominent part of the eyeball 
is called the cornea ; it corresponds to the coloured part of 
the eye as distinct from the white of the eye. The white 
of the eye is due to the white glistening fibrous coat of the 
eyeball, called the sclerotic. This serves as a protection for 
the delicate contents within the globe. The corneal part of 
the oyoljall is transparent, and allows of the transmission 
of the colour of the parts which lie within. The colour of 
the eyo is due to the pigment in the iris, a curtain which 
wjrves to control the amount of light which enters the 
interior of the eye. It corresponds to the diaphragm 
of a photographic lens, varying the size of the aperture or 
pupil through wliich the light passes. 

iioth the cornea and sclerotic, so far as they are exposed 



Expression 405 

between the eyelids, are covered by a delicate membrane, 
called the conjunctiva^ which is always kept moist by the 
secretion of the tears and thus reflects the light which falls 
upon it. In this way the 'high light', which is so important 
a detail in the drawing of the eye, is accounted for. The 
presence or absence of this high light and its position will 
vary with the direction of the light falling on the eye of the 
model. An abuse of this high light is frequently seen in 
productions of ' artist ' photographers. 

"When the eye is open the upper eyelid is withdrawn 
within a deep fold, which repeats more or less accurately 
the curve described by its free margin. Above this fold the 
tissues form a fullness which is continuous above with 
the projecting brows. Variations in the outline of these, 
details are of course numerous, and alter with the ex- 
pression and the modelling of the parts. 

Expression is in great part due to the modifications which 
take place in the form and outline of the features which 
have just been described, but the study of the subject is 
beset with many difficulties, and is by no means so easy 
as at first appears. To take a case in point, the differences 
between the expression of terror and horror are but slight, 
yet so marked that there is no mistaking them. Horror is 
not necessarily associated with fear, nor terror with disgust, 
yet both are remarkable for the general similarity in the 
mode of their representation. The analysis of these differ- 
ences requires careful study, and many subtilties are apt 
to escape the casual observer. The artist may rely on his 
models for their outward shape, but it is only exception- 
ally that he can trust to those means for the inspiration 
which quickens his forms and gives life and directness to 
their actions. 

In the study of expression, the broader effects are easily 
attained by what one may almost term conventional methods- 
It is only when the more delicate shades of difference are 



^o6 Expression 

treated that we recognize the master hand. This comes 
home to us in our experience of the stage. We acknowledge 
success and condemn failure almost intuitively. When the 
mimicry of the actor falls short of our standard of experience 
we do not hesitate to criticize his performance adversely, yet 
how often are we unable to explain the reasons of his lack 
of success ! He has failed to appeal to us because he has 
not seemed natural, for though lie lias employed all the 
conventionalities of his art he has omitted the niceties 
which infuse truth and realism into his conception. 

It is the recognition of these details and shades of differ- 
ence that enable us at once to place our finger on the weak 
spot, and it is only by prolonged study and careful observa- 
tion that we can hope to attain to anything like excellence 
in this respect. Fortunately we are able to avail ourselves of 
the experience of a great teacher. Darwin, whose book on 
the Expression of the Emotions is a masterpiece of thought- 
ful inquiry, has given us a striking exposition of the manner 
in which these problems should be attacked. The student 
will bo well repaid if he reads this book, for not only will his 
interest be aroused, but his spirit of inquiry and observation 
will be stimulated. 

It is outside the scope of this work to attempt anything 
like a full consideration of this subject, and in the following 
l>age3 only a few of the more striking facts are referred to. 

As lias been said, expression largely depends on the 
alteration in the form of the features by muscular means, but 
the student may bo reminded that action is not confined 
to tho facial muscles alone. Attitude and posture largely 
assist us in tho expression of the emotions ; the pose of 
tho lx)dy, tho turn of tho head, the position of the hands, 
Jill U'&T a part. 

Ihoro aro changes duo to other factors, as for instance 
tl»o blood-vessols and their contents. In certain conditions 
of oxcitcmont, tin, hr^rt bfuits faster, the blood-vessels are 



Expression 407 

filled with more blood, and the countenance becomes suf- 
fused. On the other hand there are emotions associated 
with a great diminution in the quantity of blood in the 
cutaneous vessels, attended by a death-like pallor of the sur- 
face of the body. These changes in the circulation react, 
too, on other organs and systems ; thus the eye becomes 
more brilliant in certain forms of excitement, due to an 
increase in the tension of its contents, whereas in other 
conditions, as in extreme prostration through fear, &c., 
it lacks much of its natural lustre. Again, perspiration is 
a result of similar influences, and curiously enough, this 
transudation through the pores of the skin is associated 
either with increase or decrease in the amount of blood 
in the cutaneous capillaries. E-eference need only be made 
to the occurrence of a cold and clammy sweat in states of 
terror to verify this fact. Blushing is also due to vas- 
cular changes dependent on nervous influence, but as the 
quality of a blush, as contrasted with a general height- 
ening of the colour, depends upon its transient nature 
it is outside the range of pictorial representation. A 
moment's consideration will enable the reader to realize 
that, whilst the contraction of the facial muscles is under 
the influence of our will, the vascular and nervous pheno- 
mena above referred to are beyond our control, and hence 
beyond our powers of mimicry, so that in representing the 
various emotions the artist must rely on his own experience 
and observations rather than on the conventional eflforts of 
his model. 

It is* with the first group of phenomena, viz. those 
due to the contraction of the facial muscles, that we 
are mainly concerned. In discussing these we must bear 
in mind that the openings on the face are each associated 
with a particular sense : the eye with sight, the nose with 
smell, and the mouth with taste ; moreover the nose and the 
mouth are also concerned with the admission of air to 



4o8 Muscles of Expression 

the lungs. The bearing of these facts will be seen here- 
after, when we come to realize that certain emotions are 
associated more or less intimately with certain of these 
senses. Thus the turning away of the eyes in shame, the 
sniffing associated with a disdainful look, and. the move- 
ments of the lips frequently observed in the expression of 
disgust, are proof of the association of these emotions with 
particular sense organs. One ashamed does not look the 
accuser in the face ; the sniffing in disdain implies that 
a person by his very odour has rendered himself offensive ; 
and in disgust the same meaning is conveyed as if by the 
movement of the lips on an unsavoury morsel. 

The muscles of expression may be grouped as follows, 
viz. those which influence the movement of the scalp, and 
particularly that part of it which forms the covering of the 
forehead, and those which control the form of the various 
apertures of the face, i. e. the eyes, nose, and mouth. 

The scalp consists of the tissues overlying the skull, from 
the brows in front, to the external occipital protuberance 
behind. The part which covers the forehead is free from 
hair, that behind forms the hairy scalp. It is loosely 
connected with the underlying bones, so that it can be 
moved backwards and forwards on them. The freedom 
of this movement varies very considerably in different 
individuals. Many possess this power to a remarkable 
degree, whilst in others it is almost absent. 

These movements are effected by the action of certain 
muscles— most important of which is the occipito -frontalis. 
This muscle consists- of two thin fleshy portions with an 
intermediate fibrous sheet, called the epicranial aponeurosis, 
Tho occipital part of the muscle covers the back of the 
head and is attached to the ridge on the occipital bone 
called tho Huperior curved line. This corresponds to the 
junction of tlio tissues of the neck with the back of 
tho head. Superiorly the fleshy fibres are connected 



Muscles of Expression 409 

with the hinder part of the epicranial aponeurosis. The 
frontal part of the muscle overlies the forehead : it has 
no bony attachment. Superiorly it arises from the fore 
part of the epicranial aponeurosis, and inferiorly is inserted 
into the skin of the brows and the root of the nose (PL, 
p. 410, Figs. I, 2, w. q. 7j). 

When this muscle contracts, as in the expression of 
surprise, it raises the sTcin of the forehead, and throws 
it into a series of folds, which repeat fairly accurately 
the curves of the eyebrows. Descending from the frontalis, 
on either side of the middle line and over the root 
of the nose, are two little muscular slips called the jpyra- 
midales nasi. These have their fixed points below, and 
are attached in part to the outer surface of the nasal bones, 
and in part to the aponeurosis which overlies the car- 
tilages of the nose. When these muscles act they therefore 
draw dozen the skin of the forehead towards the centre, 
thus causing a depression of the inner ends of the eyebrows 
and a wrinkling of the skin over the root of the nose. Such 
movements are associated with expressions of displeasure, 
as in frowning (PL, p. 410, m). 

The corrugatores supercilii muscles occupy an oblique 
position above the inner half of the brows, one on either 
side. They lie under cover of the frontalis, and arise from 
the bony arch of the orbit on either side of a^nd slightly 
above the root of the nose ; spreading outwards and up- 
wards they become attached to the skin over the middle 
of the eyebrows. When these muscles contract, the skin 
over the outer part of the forehead is drawn inwards, and 
a series of central longitudinal folds is produced. The 
muscle is usually combined in its action with the foregoing, 
that is to say either with elevation or depression of the skin 
of the forehead. In this way the transverse folds produced 
by the frontalis and pyramidales are modified in the 
middle line. In combination with the central part of 



4IO 



F o 



a: 



g 3 

y 

1 1 
o g 

«^ H 

I * 

1-1 "■ 



■^ nj ^ jj^ 



'C aJ 






15 

O O 



c ci 






c3 



W" ^ rJ 



> 

>; o ^ 



O 

^-1 rfl 






o ^d 



05^ 



rT .""^ .'-' •-" "1> ."ti .i^ 







►-J 


u 


»--< 


r/l 




«— ■ 


'O 




Aj 





bc 


J3 





ai 





*c 





^3 


05 






a 





>i 


c 




cS 




a 


CO 




H 


<; 


w 


P^ 






P4 


< 



— ! S "^ 



g a 






c3 o «> 



eS 


eS 




a 









(1> 




fl 






■73 









UJ 






=4-1 


u 


bc 







n-l 


G 


a 


-tJ 


be 


g 





tH 





c! 


<1 Ph 



,2 iJ -^ 

10 w S 

pi E3 g 

a a a 

h ^ ?s 



-•^ I— I 
* ■ 



5? 2 2 -2 -2 S 

fl "S Tl >W ••H rH •■-< 



o 



O O) 

be -ti 
tS3 -< 



3 
&< "w '3 
S o o 
W Ph O 



Ph a 



- ^ > 
o w 1^ 



H i n' - 



<^ "~'-r<oo f^oo OnO ►* f< f<5-^>ovo t^oo 



o 

P4 



ft ^ 

a> u 

4 a 






1 = 11 



o <s g 
E i; •? 



o 



.2 S itJ 

^1 i; (1) 



.w a, o •--■ 



c ^ ^ 



CO 



5 ft 

o a> 

(h _ 

ft pi 



S .2 -S -g 



f3 2 <u 



o « -S ;q 



w ^ 



e J5 



« ■ 



^(S 






.2 o 



eS 



iJ W ^ C rt 






s 

N Q c3 >^ 



0) >H ^ 12 -^i^ 



^ £ pi G OS 



a 



-2 ° 

cd 0; 
be o 

6 c« 



^ ." 



g^° 



w :;5 



-:: ^ -a 



^ s o 



'ft 
W 



o 

a > 



08 O CO .rt 
- O CO * 



W 1^ " -i flf . 

H h-1 h:] pq :^ W 



<> <ii "a V V ti 



"C'"'*^^"^ 2 C 6 C<5<vJ <»■»-! 2 ti y 




■-^ 



<i H 



'•<! "V, ■ tv. *./^ ->*v ^ 




Muscles of Expression 411 

the frontalis the corrugatores supercilii cause the eyebrows 
to become oblique, and pucker the skin in the centre of 
the forehead, as in the expression of grief. In associated 
action with the pyramidales muscles they help to emphasize 
the wrinkling over the root of the nose and lower part 
of the forehead as in frowning. If the reader will consider 
for a moment the results produced by the contraction of 
these muscles he will realize that the wrinkling of the skin 
caused by them is always transverse to the direction of 
the fibres of the muscles (PL, p. 410, Fig. i, 0). 

In passing to the consideration of the muscles of the face 
proper we recognize that they are grouped around the various 
orifices, each of which is provided with opening and closing 
muscles, in addition to others which modify their shape. 

Surrounding the fissure of the eyelids and overlying the 
Hds themselves is a thin sheet of muscle called the orbicu- 
laris palpebrarum. The fibres are arranged in a series 
of concentric loops which are attached internally to the 
inner bony margin of the orbit. Elsewhere the muscle 
spreads over the margin of the orbital hollow and is con- 
nected with the skin superficial to it. Above, it blends with 
the frontalis and lies superficial to the corrugator ; inferiorly, 
it is connected with some of the muscles of the cheek. The 
part of the muscle which overlies the lids is called the 
palpebral portion. The action of this is to close the eyelids. 
Under ordinary conditions the lower lid moves but slightly, 
the upper being drawn down over the surface of the globe. 
Exceptionally, as in the act of ' winking ', the closure of the 
lids is effected by the elevation of the lower lid. 

That portion of the muscle which lies around the lids 
is called its orbital part. The lower half of the orbital 
fibres elevates the skin of the cheek and wrinkles the 
skin over the outer margin of the orbit, producing the 
skin folds which, in old people, are often called * crows' 
feet'. The upper half draws down the skin of the forehead 



^12 The Eye in Expression 

and antagonizes the action of the frontalis. It pulls down 
the eyebrows and causes them to overhang. The muscle, 
as a whole, is employed in forcible closure of the eyes, as 
when a blow is expected. The lids are strongly compressed 
against the front of the globe, which is slightly pushed 
backward at the same time that the lids are carried a little 
inwards towards the bony attachment of the muscle (PL, 
p. 410, Figs. I, 2, 1). 

The eye is opened by the action of a muscle called the 
levator palpehrae superioris (the elevator of the upper lid). 
This muscle lies within the orbit, and is attached to the 
deep surface of the upper eyelid. Its action is sufficiently 
expressed by its name. 

The eye plays a most important part in the expression of 
the emotions. The changes met with in it are due to several 
causes. First, its brilliancy may be increased or diminished 
according as there is an increase or decrease in the tension 
of the contents of the eyeball. These changes are beyond 
our control, and are associated with exalted feelings on the 
one hand or a sense of depression pn the other which react 
on the circulation. In the former state the eye is bright, 
whilst in the latter it appears dull. An increase in the tears 
which Ijatho the surface of the eyeball leads to the more 
ready reflection of the light from the moist, exposed surfaces. 
An excessive increase leads to the shedding of the tears, 
which takes place in certain violent and uncontrollable 
emotions. 

The movements of the eyeball, which are distinct from 
those of the eyelids, have a definite influence on expression. 
Tho downcast eye indicative of shame, the upturned eye 
sujrgoHtive of devotion, tho averted eyo associated with 
the expressions of disgust and aversion, the downward 
and sid.tlong look in contempt, are all well-marked ex- 
urn pies. 

lastly, wo have tho relation of the opening of tho eyelids 



The Eye in Expression 413 

to consider. In such emotions as surprise, terror, and horror 
the eyes are widely opened. The partial closure of the 
lids may be associated with a contemptuous look, in which 
there is a suggestion that the person is not worth looking 
at, and that we would experience little loss if we shut him 
out from our sight. Narrowing of the opening between 
the eyelids is often seen in people whose attention is con- 
centrated on some thought, or who are gazing steadfastly at 
some object. Here it is often combined with a slight frown. 
The purpose of this action may be either to allow less light 
to enter the eye or to shut out surrounding objects. 

The eyelids are forcibly closed when we expect to receive 
a blow or sudden shock, and one of the first difficulties 
a novice in boxing has to overcome is to control this 
tendency. Here the closure of the lids is obviously for the 
purpose of protection. In like manner, in such violent 
expiratory acts as sneezing and coughing, the eyeballs 
are supported by the closed lids. In laughter the orbicular 
muscle is contracted, the skin around the eye is wrinkled, 
and the opening between the eyelids is narrowed. 

Apart altogether from the influence of the eye on expres- 
sion, the student should note the delicacy of the skin below 
the lower eyelid and on the inner side towards the root 
of the nose. Here the cutaneous vessels exercise a marked 
influence on the surface colour. In some, a dark tint often 
enhances the brilliance of the eyes. The general recognition 
of this fact has led to its adoption by artificial means in the 
art of ' making up '. 

The eyebrows and eyelashes differ in different individuals. 
The former should be well arched and separated by an 
interval. The latter vary in their length and in the character 
of their sweep. Dark eyelashes mask to a certain extent 
the drawing of the margin of the lids, as they surround 
the opening of the eyelids with a dark indefinite zone. 
The colour of the eyebrows and eyelashes need not neces- 



^i^ Muscles of the Nose 

sarily conform with that of the hair. It is by no means 
uncommon to meet with women with fair hair and dark 
eyebrows and lashes, though it may here be pointed out 
that the same results may be obtained by the practice of the 
mysteries of the toilet. 

Though man is unable to open and close the nostrils, he 
yet possesses a considerable amount of control over the size 
of these apertures. This is effected by the movements of 
the nasal cartilages. The reader must bear in mind that the 
nose is not only the organ of the special sense of smell, 
hut is also one of the channels through which air passes 
to and fro in respiration ; hence the muscles which control 
the movements of these cartilages are concerned with the 
changes in the form of the nostril which accompany forced 
respiration, as well as those which are associated with the 
perception of smell. 

Of these muscles the most important are the compressor 
7uiris^ the levator alae nasi, and the depressor alae nasi. 

Tho compressor muscles are placed on either side of the 
nose. They arise from the upper jawbone, close to the bony 
margin of the nasal aperture. Spreading out in a fan- 
shaped manner on the sides of the nose, they are inserted 
into a thin aponeurotic expansion which stretches across . 
tho bridge of the nose. Overlying, as these muscles do, the 
cartilaginous part of the nose, when they contract they tend 
to depress the cartilages and so compress the alae, as they 
overhang the nostrils (PL, p. 410, Figs, i, 2,j), 
. Thfi hvnior alae nasi forms part of a muscle called tho 
letator lahii superioris et alae nasi. It takes origin above 
irom tho bono in front of the orbital margin, and close to 
the root of tho nose ; its fibres pass downwards along the 
«ido of the no8o and are inserted into the wino-s or alae 
01 Uio nostril. As its name implies, this muscle raises the 
wmgs of the nose and henco dilates tho nostril, as in the act 
of snifling. Its action is associated with an elevation of the 



The Mouth 415 

upper lip at the same time, owing to the fact that some 
of the fibres which arise from the same bony attachment 
pass down to be inserted into the upper lip ; hence the 
name given to the whole muscle (PL, p. 410, Figs, i, 
., Tc). 

The depressor alae nasi takes origin from the upper jaw- 
bone, immediately above the front teeth. Its fibres pass 
upwards to be inserted in part into the septum of the nose, 
in part into the posterior aspect of the wings of the nostril. 
The muscle draws down the septum and assists the com- 
pressor in depressing the alae of the nose and narrowing 
the nostril. Under ordinary circumstances the movements 
of the alae are imperceptible in respiration. In violent 
inspiratory efforts, after prolonged muscular exercise, or in 
conditions of intense excitement accompanied by deep 
inspirations, the dilatation of the nostrils becomes a charac- 
teristic feature. When we wish to analyze more care- 
fully the nature of a particular odour we draw the air up 
forcibly into the nose and then contract the orifice so as to 
prevent its escape. These are the sniffing movements, move- 
ments which are often the involuntary accompaniment 
of such expressions as contempt and disdain (PL, p. 410, 
Figs. I, 2, i). 

Of all the features, the mouth is the most mobile and the 
most under our control. Though many of its movements 
are in a sense involuntarily associated with certain moods, 
yet they may be checked by the exercise of the will. 
In like manner we can, with a certain degree of success, 
simulate by the voluntary contraction of some of its muscles 
the expressions which are habitually dependent on the more 
or less co-ordinated action of these muscles. 

The mouth ranks first therefore as a modifying agent in 
the appearance of the features. The slight upturning of 
the angles of the mouth imparts to the face an altogether 
different appearance from that displayed when the angles 



4i6 Muscles of the Mouth 

are down-drawn. In support of the view tliat the mouth is 
such an important factor in the determination- of expression, 
we have only to take into consideration the number of 
muscles which surround it. 

Generally speaking, the muscles of the mouth may be 
divided into groups according to their action. There is 
a closing muscle called the orbicularis oris. There are 
muscles which raise the upper lip, others which elevate the 
angle ; some which retract the angles, and some which draw 
them down; and, finally, there are those which depress 
the lower lip. 

The orbicularis oris consists of an oval sheet of muscle 
of considerable thickness which surrounds the orifice of the 
mouth. Its inner edge corresponds to the red margins of 
the lips. Its outer border spreads upwards towards the base 
of the nose, outwards towards the cheek, and downwards as 
low as the furrow which separates the lower lip from the 
chin. The muscle is connected by slender slips with both 
upper and lower jaws, above and beneath the front teeth. 
The bulk of the muscle, however, is made up of fibres which 
pass across from side to sMe and turn upwards and down- 
wards at the angles of the mouth. The outer border 
of the muscle is blended with the various elevators and 
flepressors of the lips and angles, and is also intimately 
connected with the muscles of the cheeks. The muscle 
closes the mouth and brings the lips together; it also 
narrows the mouth and causes the lips to protrude (PL, 
p. 410, Figs. 1,2,(7). 

The elevators of the upper lip are two in number. One 
has boon already in part described, viz. the levator labii 
Mitperioris et alae nasi The fibres of this muscle which pass 
to the lip are blended with the orbicularis on either side 
of the wings of the nostrils (PI, p. 410, Figs, i, 2, h). 

The hmior lahil superioris proprius^ or special elevator 
of the upper lip, arises from the front of the upper jaw-bone. 



Muscles of the Mouth 417 

close to the lower margin of the orbit ; it is more or less 
united with the preceding muscle, and is inserted into the 
tissues of the upper lip (PL, p. 410, Figs, i, 2,5). • 

The elevators of the angles of the mouth are the levator 
anguli oris and the zygomaticus major and minor. 

The levator anguli oris arises from the front of the upper 
jaw-bone under cover of the levator labii superioris pro- 
prius, and passes downwards and slightly outwards to be 
inserted in the upper border and outer side of the angle of 
the mouth (PL, p. 410, Figs, i, 2, t). 

The zygomatici are two muscular slips which arise from 
the outer surface of the cheek-bone and pass downwards and 
forwards to reach the angle of the mouth, where they are 
inserted (PL, p. 410, Figs, i, 2, h). 

All three muscles are elevators of the angles of the 
mouth, but the latter tend to draw the angles upwards 
and outwards, as in the broad grin, whereas the levator 
anguli oris tends to intarn the angle. 

"We have already seen how the platysma myoides (p. 374) 
passes up from the neck on to the face to be connected with 
the muscles of the lower lip. Some of its more specialized 
fibres have received a definite name, and constitute the 
risorius muscle. These fibres arise from the fascia of the 
cheek in front of the ear, and, passing forwards, are attached 
to the skin of the angle of the mouth. They act as retractors 
of the angles and thus widen the mouth (PL_, p. 410, Figs. 

The depressors of the angles of the mouth include the 
depressor anguli oris and the fibres of the platysma which 
are passing to the angle. 

The depressor anguli oris arises from the lower jaw near 
its lower border, on either side of the middle line. The 
muscle, which is triangular in shape, and is hence some- 
times called the triangular muscle of the chin [triangularis 
mentijj is attached by its pointed extremity to the tissues 

THOMSON E e 



^i8 Muscles of the Mouth 

of the angle of the mouth on its lower side. The fibres of 
the platysma have been already referred to. 

Both these muscles pull down the angle of the mouth, 
the platysma at the same time drawing it backward and 
outwards (PL, p. 410, Figs, i, 2, e). 

The depressor muscle of the lower lip is the de;pressor labii 
inferioris. It arises from the front of the lower jaw under 
cover of the depressor anguli oris. Square in shape, and hence 
sometimes called the quadratus menti, it passes upwards and 
is inserted into the tissues of the lower lip, blending with 
the orbicularis oris. The action of this muscle is assisted by 
the fibres of the platysma (PL, p. 410, Figs, i, 2, d). 

The levator menti is a small muscle which arises from the 
front of the lower jaw, below the front teeth. Running down- 
wards and forwards, it spreads out and is inserted into the 
skin of the chin. By raising the chin^, as its name implies, 
it also elevates the lower lip and protrudes it (PL, p. 410, 
Fig. 2, c). 

The action of the various muscles on the form of the 
mouth has been referred to as each has been described, but 
a moment's reflection will enable the reader to understand 
the complexity of form which is the result of their combined 
action. Not only is this the case when the lips are closed, but 
an altogether different shape may be given to the open 
mouth by the squaring of the angles, or the inturning and 
protrusion of the lips. 

Not« also how the mouth is, like the nose, associated with 
a special sense, viz. that of taste, and also with the respiratory 
function. In association with taste we frequently have 
movements cxprossivo of pleasure or disgust, movements 
such as would be performed by the lips on the reception 
of a tasty bit or the rejection of an unsavoury morseL 

Tho mouth is not only a channel through which air may 
ont^jr and pa.ss irom the lungs, but also exercises an important 
influence in speech and voice-production. In making 



The Month in Expression 419 

a violent muscular effort after the chest has been filled with 
air the mouth is firmly closed, as if to prevent its escape. 
On the completion of the act the mouth is again opened 
and the air expelled from the lungs. Under ordinary and 
healthy conditions the nose alone suffices for the purposes of 
respiration, but under exceptional circumstances, when the 
respiratory efforts are much increased, the mouth is often 
made use of to enable us to get more breath. So delicate 
and precise are the forms given to the lips in speech, that 
advantage is taken of this circumstance to enable the deaf 
and dumb to read by sight the words which fall from the 
lips of a speaker they cannot hear. A striking example 
of the characteristic appearance of the mouth and lips in 
the production of certain notes is seen in the figures on 
the sculptured frieze executed by Luca della Eobbia, in 
conjunction with Donatello, for the organ gallery of the 
cathedral at Florence. The visitor to the Uffizi Gallery has 
little difficulty in determining from the expression of the 
singers the character of the voice. 

The mouth is opened widely in surprise and awe. So also 
in disgust and laughter, though the forms are very different. 
A vacant, silly look is often given to the face by an Open 
mouth. 

A firmly closed mouth is expressive of determination. 
The closure of the jaws and the opening of the mouth so 
as to show the clenched teeth are- suggestive of hatred, and 
hint at the use of the teeth as weapons of offence. 

The upturned angles are characteristic of the merry 
moods, whilst a down-drawn mouth is associated with less 
pleasant emotions. 

In connexion with these alterations in the shape of the 
mouth it is well to note how furrows, which play an 
important part in expression, become developed. The 
most important of these is the naso-lahial furrow. This 
separates the rounded form of the cheek from the wing 

E e 2 



.20 Expression 

of the nose, and, sweeping downwards and outwards, fades 
away imperceptibly towards the angle of the mouth. 
Coincident with certain movements of the mouth, this 
furrow is emphasized and altered in its direction. In 
lauo-hter and crying it is much deepened and curved. 
It is deepened above, when the skin on the side of the 
nose is drawn up and wrinkled, and it is straightened 
when the angles of the mouth are depressed. The furrow 
may either be carried round the angle of the mouth, or 
may be replaced by another which continues the curve 
of the upper lip downwards and outwards. 

Reference has been already made to the association of 
facial expression with gesture and pose of the body. 
Gesture and pose express the emotions on a large scale, the 
face being concerned rather with the subtilties and details. As 
Professor Cleland ^ has pointed o^it, gesture largely depends 
on the association of mental with physical conditions. 
Moral rectitude, as expressed in indignation, is associated 
with a straightening of the figure; mental depression 
is indicated by a lack of energy in the movements of the 
body. 

In like manner certain emotions are expressed by gestures 
whif'h have a purely physical basis. We often convey the 
meuning that we wish to avoid or shun a thing by putting 
up the hands as if to push it aside. We bend the body 
forward and incline towards what pleases us, or indicate 
by th(! direction of a wave of the hand whether we desire 
a pirson to a])proach or leave us. These examples are 
Hufliciftut to enable the reader to appreciate the physical 
reasons for the gestures so frequently employed. 

In i)roviding a short summary of the more striking 
charact<3ri8tics of some of the expressed emotions, the details 
must necessarily bo brief and the selection far from complete. 

• Erolution, Krpr.ssion, and Sensation, hy John Clehind, M.D., F.R.S. 
CilMgow : .liimcH Maclehose. 



Expression 421 

Sir Charles Bell ^ laid it down as a general rule that 
'in all the exhilarating emotions the eyebrows, eyelids, 
the nostrils, and angles of the mouth are raised ; in the 
depressing passions it is the reverse '. 

To this may be added the suggestive remarks of Professor 
Cleland, that ' expression for the information of others 
is most liable to be made with the mouth, the organ of 
communication with the world ; while expressions that 
betray thoughts unintentionally to the outer world are 
most liable to begin in the eye and forehead.' 

In the expression of suffering as shown in a crying 
child we see the eyes firmly closed and the skin around 
them puckered. The skin of the forehead is drawn down 
and wrinkled by the corrugators and pyramidales so as 
to cause a frowning appearance. At the same time the 
skin of the nose is wrinkled and the upper lip drawn up, 
and the angles of the opened mouth are somewhat squared 
by the antagonizing influence of the depressor anguli oris. 

Such expression is characteristic of a child 'roaring' 
with pain or temper, but, as Professor Cleland has remarked, 
the expression is very much akin to that of an adult 
' roaring ' with laughter. In proof of which we need only, 
as he points out, make the experiment with one of Darwin's 
own illustrations ^ by covering with a card all but the head 
of the child ; then sketch on the card the hgure of a fat 
old man lying back in his chair, and the child's face, 
without a stroke of change, will be converted into the bald 
head of the old man convulsed with laughter. Laughter, 
sobbing, and crying, as Professor Cleland points out, have 
the feature in common of convulsive breathing ; the appear- 
ances are not dissimilar, and the value of the above experi- 
ment depends on the association of ideas. ' Old men are 

^ The Anatomy of Expression. Third edition, 1844. 
- Expression of Emotions, by Chas. Darwin, Plate i, Fig. 2. John 
Murray, London, 1872. 



422 Grief— Laughter — Reflection 

more given to roar with laughter than to bellow like 
children.' Hence the very different interpretations placed 
upon the expression. 

In prolonged grief the face is pale, the eyelids droop, 
and, owing to the flaccid condition of the muscles, the lips, 
cheeks, and lower jaw all sink down by their own weight. 
By the contraction of the central portion of the frontalis 
and the two corrugators the eyebrows are drawn upwards 
towards the centre of the forehead and assume an oblique 
direction, whilst the skin of the forehead is wrinkled, with 
rectangular furrows towards its centre. The drooping of 
the head on the chest is also characteristic of this form 
of emotion. 

Laughter is expressed by the opening of the mouth, the 
angles of which are either drawn back, as in the broad 
grin, or drawn back and upturned. The upper lip is 
slightly raised, the naso-labial furrow is deepened and 
curved round the angles of the mouth. The skin over 
the nose is finely wrinkled, and the eyebrows are slightly 
lowered. The eyes are partially closed by the contraction 
of the orbicularis palpebrarum, which also wrinkles the 
skin around the lids. The eyes themselves are bright and 
sparkling, due to the acceleration of the circulation within 
thorn. 

Devotion is associated with an upturned face and eyes, 
and liands either clasped or crossed on the breast. 

licfloction, abstraction, and meditation are characterized 
by slight frowning movements and a vacant look in the eyes, 
due to the fact that we are * staring at nothing in particular'. 
The eyes arc not concentrated on any object, and sometimes 
aro slightly divergent, convoying just the suggestion of 
a Hfjuint 

111 temper is suggested by a frown and the depression of 
tlH3 angles of the mouth ; sulkinoss, by a pouting of the lips, 
accoiiiiani.Ml with a downward turn of the angles. 



Rage — Sneering — Disdain 423 

Determination is indicated by a firm closure of the 
mouth, accompanied by a deep inspiratory effort, at the 
same time that the whole muscular system is ready for 
action. A nod, as when a person says ' I'll do it ', frequently 
accentuates the expression. 

Shyness, on the other hand, is often associated with 
blushing and a desire to avoid looking one in the face, 
as suggested by the averted or down-turned head. Shyness 
and shame are very much alike, though the former is 
often distinguished from the latter by a pouting of the lips. 

In rage the circulation is much affected ; the face reddens 
and the veins of the neck and forehead become distended. 
In other cases pallor is a marked feature; the person so 
affected becomes ' white with rage '. The chest heaves 
with the more violent respiratory efforts, and the nostrils 
quiver, the mouth is closed, and the teeth are firmly 
clenched. At times the lips are protruded, or, it may be, 
retracted, so as to show the teeth. The brows are frowning, 
and the eye is bright and flashing ; the hair may bristle, 
and the voice is affected — it ' sticks in the throat ' and is 
often trembling and discordant. The fists are frequently 
closed as if to strike, but in extremes of passion the move- 
ments of the hands and arms may be purposeless. 

Indignation differs only in degree from rage. The pulse 
is slightly quickened and the colour heightened ; the eye is 
bright, and the wings of the nostrils are raised ; the mouth 
is commonly compressed. Respiration is hurried, and the 
figure is drawn up and the head thrown somewhat back. 

Sneering is characterized by an upturned and averted 
face, and a retraction of the upper lip so as to expose the 
' eye ' or ' canine ' tooth. As Darwin has pointed out, this 
reveals man's ancestry, for the action is the same as that of 
a snarling dog when showing his fighting teeth or canines, 
preparatory to a tussle with his antagoi;List. 

In disdain the expression is accompanied with a partial 



^24 Fear — Terror 

closure of the eyelids, as if the person looked at were 
disagreeable to the sight or unworthy of a glance. In 
contempt the upturned and wrinkled nose suggests an 
offensive odour, whilst in disgust the movements of the lips 
or the clearing of the throat convey the impression that the 
person so moved is endeavouring to rid himself of an ill 
taste or some unsavoury mouthful. 

Helplessness is usually suggested by elevated eyebrows 
and wrinkled forehead. The mouth is usually open and the 
head bent to the side. The elbows are placed by the side, 
and the palms are upturned and open. A shrug of the 
shoulders helps to emphasize the expression. 

The expressions of attention, surprise, astonishment, and 
terror are closely allied, and may succeed each other in 
an apparently natural sequence. In attention the eyebrows 
are elevated and the forehead is wrinkled, and the opening 
of the eyes and mouth corresponds to the degree of sur- 
prise or astonishment. In admiration the same appearances 
are seen, but here the mouth expands into a smile, and the 
eye brightens. 

Fear, on the other hand, is accompanied by pallor. 
A clammy sweat often breaks out on the surface of the 
skin, tlie mouth is dry, the heart beats violently, and 
there is trembling all over. 

In terror these phenomena are all accentuated. A deathlike 
pallor overspreads the surface. The nostrils are dilated and 
the breathing is laboured. There is gulping of the throat 
and a convulsive movement of the lips. The eyeballs 
protrude and roll from side to side; the cheeks are 
trombling, and beads of perspiration roll down them. The 
violent contraction of the platysma causes the wrinkling 
of tliH skin of the side of the lower jaw and \ieck, and 
drap* down the angles of the opened mouth. The person 
BO am-ctcd is utterly ininorvod and bordering on a state 
of collapse. 



Horror — Habitual Expression 425 

Horror, as distinct from terror, is characterized by con- 
tracted brows with no loss of energy. The body is in a 
state of extreme tension, but the victim of this sensation 
is not unnerved by fear, and has not lost control over his 
actions. 

In conclusion, it is merely necessary to remind the reader 
that when an expression becomes habitual the cast of the 
features is moulded thereby. The face of a sleeping child 
is calm and expressionless ; it is as it were the clay on which 
nature is going to stamp the character of the man, for 
expression uncontrolled is but the outward evidence of the 
working of the mind. According to the disposition of 
the individual, so the features become set. "We recognize 
a morose and ill-tempered man by his look, for in him 
the habitual mood has become more or less permanently 
expressed by every feature in his face. 

One example is sufficient to enable the reader to recall 
many others in which the general temperament is as charac- 
teristically displayed. 



CHAPTEE XLV 



PROPOETION 



A CANON of proportion in strict accordance with scientific 
measurements would result in mere commonplace. Science 
seeks to attain an average, art an ideal. The artist searches 
for his models amongst those who display the most graceful 
and refined types of manly strength and feminine beauty, 
whilst the anthropologist and anatomist are content to 
measure all, good, bad, and indifferent, in their endeavours 
to strike a mean. 

As every artist knows, it is impossible to find a model 
without blemish. The ideal conception depends on the 
selection from different models of those features which are 
most pleasing, the combination forming a masterpiece very 
different from the vulgar average put forward by the 
anthropologist as typical of the race. The scientific criticism 
of proportion as applied to art is therefore misleading, 
and, far from aiding the artist, is like to sink him to the 
level of the mere chronicler of facts. For such as desire 
the iiilbrmation there are many works in which the subject 
is di.scussfid from a scientific standpoint. Here it is neither 
my intention nor desire to trouble the reader with details 
which, however interesting, have little to do with his art 
education. 

The main difficulty which has always presented itself in 
iliw conm;xi(,n is the unit of comparison which is the 
\MiHi U) adopt. Vor draughtsmen who are not constructing 
human figuns on gi-omotrical principles with rule and 
coMipuMs it is impr.rtant that tlio unit employed should be 



Proportion 427 

easily compared with the rest of the figure. The head, 
face, hand, foot, and middle finger have all been selected 
by different artists and anatomists for this purpose. 

The history of the subject is by no means uninteresting, 
and should the reader desire to extend his knowledge 
further in this direction he may consult with advantage 
a work entitled Proportions of the Body^, in which he 
will find a short account of the more important facts. 

The scheme proposed by Dr. Paul Richer in his admirable 
treatise on Artistic Anatomy - seems by far the best. It 
is not too elaborate, and is admirably adapted to serve 
as a guide to the draughtsman. Dr. Richer's method 
is based on that of Cousin, in which the head is taken 
as the unit of comparison. This corresponds to the length 
between two horizontal lines, the one passing on a level 
with the top of the head, the other with the point of the 
chin. The height of the figure is equal to 7^ heads. 
This corresponds to the proportion of the head to height 
in the Antinous. The Gladiator and the Farnese Hercules 
measure 8 heads, as also the Venus of Milo. The tendency 
in the antique is to keep the head small in proportion 
to the figure. In this way a sense of height and dignity 
is attained. 

From the chin to the fork measures 3 heads, distributed 
as follows. From the chin to about the level of the 
nipples, I head ; from this level to a point a little 
above the navel, i head ; from this to the fork, which 
corresponds posteriorly to the fold of the buttocks, i head. 
A rough-and-ready method for sketching in the pro- 
portions of the trunk is to divide it into thirds, of 
which the lowest includes the distance from the seat 

^ Proportions of the Body, by Prof. B. C. A. Windle. Bailliere, Tindall, 
& Cox, London, 1892. 

2 Anatomie Artistique, by Dr. Paul Richer. E. Plon, Nourrit, et Cie., 
Paris, 1890. ' 




PEOPORTIOKH OK maI.I: ANI. ..KMAM-: FIUUUKH in heads and IIALF-IIEADS 



Proportion 429 

to the waist, the middle that from the waist to the 
shoulders, whilst the highest is apportioned to the head 
and neck. 

The limbs bear the following proportion to the head. 
The lower extremity, when straight, measures 4 heads 
from the heel to the trochanter major, and thus equals 
in length the head and trunk together. From the under 
surface of the heel to the articular surface of the knee 
measures 2 heads. From the articular plane of the knee 
to the middle of the furrow of the groin the distance 
is 2 heads ; from the plane of the knee to the highest point 
of the iliac crest, about 2\ heads. 

As 4 heads have been measured from the top of 
the figure to the fork, and 4 heads up from the heels, 
and as the height of the figure equals 7^ heads, it follows 
that the distance between the levels of the fork and the 
trochanters measures half a head. The half of this distance, 
which overlies a point on a level with the summit of the 
arch of the pubis, corresponds to the centre of the figure, 
being distant from the top of the head and sole of the 
foot 3I heads respectively. 

From the heel to the fork the limb measures 3^ heads, 
and the centre of the patella corresponds to the middle 
of the distance between the anterior superior iliac spine 
and the sole of the foot. 

In the seated figure, with the thigh flexed at right angles 
to the trunk, and the leg bent at right angles to the thigh, 
the distance from the top of the head to the seat equals 
4 heads. The length of the thigh from the back of the 
buttock to the front of the knee is about 2^ heads or over, 
whilst the height from the ground to the upper surface of 
the bent knee equals the distance from the under surface 
of the heel to the articular plane of the knee (2 heads), plus 
the thickness of the lower end of the thigh, the total coming 
to somewhat less than 2 J heads, say 2.\ heads. 



.^o Proportion 

The arm is 3 heads long from the bottom of the hollow 
of the armpit to the tip of the middle finger. Of this the 
fore-arm and hand, from the tip of the middle finger to 
the tip of the elbow (olecranon), measure 2 heads. The 
length from the summit of the shoulder (the point where 
the collar-bone articulates with the acromion process of 
the scapula) to the bend of the elbow equals the length 
from the bend of the elbow to the elevation on the palm 
of the hand overlying the root of the middle finger. 
With the upper arm by the side and the elbow bent at 
a right angle the distance from the tip of the acromion to 
the under surface of the bent elbow is about i^ heads. 
With the arm by the side, the wrist lies on a level 
with the central point of the figure, and the fingers 
reach a little below the centre of the thigh, taking that 
as a point i head distant from the articular plane of the 
knee. 

In regard to the breadth of the figure the following 
measurements are approximately correct, though liable to 
great individual variation. The greatest width of the 
shoulders is equal to two heads, the greatest width across 
the hips should be i| heads, whilst the narrowest part 
of the waist is a little more than i head. The width 
between the nipples is equal to, or a little less than, a head ; 
and the distance between the two anterior superior iliac 
Bpinos is about a head or a little over. 

Til r. -^anl to some other proportions of the trunk, the 
vcriical distance between the collar-bone, when the arm 
18 by the side, and the anterior superior iliac spine of 
tho same side is 2 heads. The waist, or what corresponds 
to it, the free margin of the ribs, lies i\ heads below the 
level of the collar-bone. From the level of the spine of 
the seventh cervical vertebra on the back to the level 
of the depressions over the posterior superior iliac spines 
u 2 heads. The lower angles of the shoulder-blades, 



Proportion 431 

when the arms are by the side, reach a level niidway 
between these two points ; in other words, they lie a 
head below the level of the spine of the seventh cervical 
vertebra. 

The head is divided into two equal parts by a horizontal 
line passing through the angles of the eyelids : these 
halves are again equally divided, so that the head is 
apportioned into four parts, of which the highest includes 
the hairy scalp, the second the forehead and eyebrows, the 
third the nose, and the fourth the mouth and chin. This 
arrangement, as has been pointed out, leaves but a short 
space for the mouth and chin, and the suggestion of Da 
Vinci, that the distance between the chin and the eyebrow 
be halved and made to correspond with the base of the 
nose, appears to meet with general acceptation. Lanteri 
gives the distance from the ear to the point of the nose, as 
equal to that from the chin to the eyebrows. The ear is so 
placed that the upper border of it lies on a level with the 
highest point of the eyebrows, whilst its lower edge usually 
falls on a horizontal line passing through the nostrils. It 
need hardly be pointed out that great individual variations 
may occur in the relative proportions of the features. 

The breadth of the head on a level with the eyes varies 
much in different individuals and races ; a good proportion 
appears to be that this width should equal three-quarters 
the head length — in other words, the face and forehead. 
According to Cousin, this width may be divided into five 
equal parts, of which the central division corresponds to 
the interval between the eyes. On either side of this the 
ej^es each occupy a division, whilst external to these 
the outer orbital margins and the temples seen in per- 
spective go to make up the outer fifths. The base of the 
nose is said to equal an eye in width, and the mouth, 
which varies greatly, may be stated as equal in width to 
\\ eyes. The width of the neck is usually about half 



432 



Proportion 



a head, and the length from the chin to the pit of the 
neck varies from a quarter to one-third of a head. This 
distance is increased or diminished according as the head 
is raised or depressed. 

The table subjoined, which is mainly taken from Dr. 
Richer's excellent treatise, will appeal to the student as 
eminently practical and not unduly detailed. 



II A LP 

IIead = 



/The length of the middle finger, including the head 

of its metacarpal bone, as when flexed. 
The height of the flank as seen from the front, i. e. 
the distance from the anterior superior iliac spine 
to the free margin of the ribs above. 

\The furrow between the buttocks. 



One 

II FAD = 



{ 



Onk AM) 
A IIALK 

nr:AD8=: 



/The distance from the chin to the line of the nipples. 

The distance from the level of the nipples to the 
navel. 

The length of the arm from the hollow of the arm- 
pit to a point a little above the bend of the elbow. 

The length of the hand, including the wrist. 

The height of the buttocks. 

The distance which separates the two hollows above 
the collar-bones. 

The height of the scapular region from the superior 
])order of the trapezius to the lower angle of the 
Bhouldor-blade. 

The width between the two anterior superior iliac 

, Bpinos, which slightly exceeds a head. 

The hciglit of the chest-wall from the summit of 
tlio shoulder to the upper limit of the flank. 

The width between the two shoulder-joints. 

The width across the hips between the two tro- 
chanters. 

The distance between the fork and the articular 
I»luno of the knee-joint. 

IIh- (h'stnnco from the acromion to the under surface 

. of th«! bent elbow. 



Proportion 



433 



Two / 
Heads = \ 



Two AND 
A HALF 

Heads = 



Three 
Heads = 



^Tlie leg from the sole of the foot to the articular 
plane of the knee. 

The thigh from the articular plane of the knee to 
a point immediately above the great trochanter, or 
to the level of the middle of the fold of the groin. 

The fore-arm and hand from the tip of the middle 
finger to the tip of the elbow (olecranon). 

The height of the trunk from the collar-bone in 
front to the anterior superior iliac spine, and 
from the spine of the seventh cervical vertebra 
behind to the level of the depressions overlying 
the posterior superior iliac spines. 

The distance from the back of the buttock to the 
front of the knee in the seated figure. 

'The height of the torso from the chin to the fold 

of the buttocks. 
From the top of the head to the navel, or to the 
■{ upper limit of the buttocks behind. 
The length of the upper extremity from the bottom 

of the hollow of the armpit to the tip of the 

middle finger. 
/From the top of the head to the. fork, or the fold 

of the buttocks behind. 
I The length of the lower limb from the sole of the 

foot to the top of the great trochanter. 

The centres of the shoulder-joints lie i| heads from the top of 
the head. The centres of the hip-joints lie 3J heads from the top 
of the head, or 4 heads from the ground. 

Added to the foregoing are the following details,, which 
have been collected from various sources. They do not 
profess to be absolutely accurate, but may aflford the 
student a ready means of testing approximately the pro- 
portions of his drawing. 

/7J to 8 head lengths. 
6 to 7 foot lengths. 
9 to 10 hand lengths. 

4 cubits (i. e. the distance from tip of middle finger 
to tip of elbow). 

Ff 



Four 
Heads = 



Height 
OF Figure = 



434 



Breadth 
OF Figure 



Proportion 



OXE 

FooT = 



f 2 heads, or more than one quarter of 
Shoulder = I j^^igj^j_ 

Waist = I foot, or little more than i head. 
Hips = I J heads, or one-fifth of height. 

/One-sixth to one-seventh of height. 
Length of ulna. 
Width of waist. 

1 Depth of trunk in profile on a level with the nipples. 
Twice the length of face from eyebrows to chin. 
Circumference of fist. 



Three feet equal the distance from the sole of the foot' to 
the fork. 

One-ninth to one-tenth of height. 

A face length (three-quarters of a head). 

Horizontal depth across profile figure : 

(a) From lips to back of neck. 

(6) At level of navel. 

(c) Across middle of thigh. 
Distance along side of chest, from waist to anterior 
fold of armpit with arm by the side. 



One 

Hand = 



{ 



A Hand 
(less the 
torminal 
joint of the 
niiddio 
finger) = 



/Length of collar-bone. 

Length of inner border of shoulder-blade. 

Breast-bone without ensiform cartilage. 

Interval between inner borders of shoulder-blades 

wlion arms are by the side. 
\Half the length of the humerus. 



It is not necessary to enter into a detailed account of 
the proj)ortions of the long bones. The following table may 
serve as a guide, which will for all practical purposes be 
found sufhcient. 

The thigh-hono (femur) = 2 heads length. 

The. fthin l>ono (tibia) = a little more than i^ heads. 

Tlif. how of tlio uj,j,or arm (humerus) = about i| heads. 

Th« outiT bonn of the fore-arm (radius) = about i head, or half 

th<' length of the femur. 
The inn.T bone of the fore-arm (ulna) = i foot length. 



Proportions of Female 435 

Thp collar-bone, the inner border of the shoulder-blades, and the 
breast-bone without the ensiform cartilage are all of nearly equal 
length. 

The length of the axis from the top of the head to the tip of the 
coccyx is veiy nearly half the length of the figure. 

In passing to discuss the relative proportions of the 
male and female figure it will be necessary, in the first 
instance, to say something about the characteristic differ- 
ences of the female skeleton. The bones of the female are 
smaller and more slender, and do not present the rough 
surfaces which in the male are associated with a more 
powerful muscular system. 

The form of the thorax is not only smaller in all its 
diameters than that of the male, but is also proportionately 
shorter. In accord with this we find that the breast-bone 
is proportionately shorter than in the male. 

The form and size of the pelvis are amongst the most 
distinctive features of the female skeleton. They have been 
already referred to (p. 250), but some of the more important 
facts may here be recapitulated. It is wider and shallower 
than in the male ; the sacrum is wider, and projects further 
backwards (Fig. 209). The greater width of the female 
pelvis accounts for the greater breadth of the female figure 
in this region, for not only are the iliac crests and their 
extremities, viz. the anterior superior iliac spines in front, 
and the posterior superior iliac spines behind, more widely 
separated from their fellows of the opposite side than in 
the male, but the acetabular hollows for the reception of 
the heads of the thigh-bones are further apart, which gives 
increased breadth to the thighs below (Fig. 205). Owing 
to the pelvis being more shallow in the female than in the 
male the distance between the iliac crests and the thoracic 
margin is increased (Figs. 210, 211), whilst the dis- 
tance from the iliac crests to the tops of the trochanters 
of the thigh-bone is diminished ; in other words, the 

r f 2 



43^ 



Proportions of Female 



flanks are longer in women, and the buttocks do not reach 
so high as in the male (PI., p. 86). Since the anterior 




Fig. 204. The male pelvis. 




^ ^^1/7*';.'" '''•'• '""'-''"-turn. 

^ An..Hor.np«r|..riI.a.„pi„,, 
/ An.onorn.fcnoriliHc ,,,.,. ^ 



r^in. 205. The female pelvis. 



g. Acotabulum. 
h. Pubic arcli. 
k. Pubic 8.vm])liysi3. 
#. Spine of pubis. 

Tlio sacrum is soon wodRod in bctwocn 
tho two innominate boues behind. 



Female Figure 



437 



superior iliac spines lie at a lower level and wider apart- 
than in the male, it follows that Poupart's ligament and 
the furrow of the groin which overlies it are more horizontal 
than in the male, in whom they tend to more nearly approach 
the vertical (Pis., pp. 72, 216, 298, 434). 

As has been already pointed out, the ' obliquity ' of 
the pelvis (p. 261) is more marked in the female than in 
the male (Figs. 210, 211). This leads to characteristic 
appearances in the form of the thighs, back, and buttocks ; 





Fig. 206. 



Fia. 207. 



Diagrams showing the greater degree of obliquity of the thigh-bones 
dependetfit on the greater pelvic width in woman. Fig. 206, as compared 
with man, Fig. 207. 

of these it is only necessary here to mention the more pro- 
nounced forward curves in the lumbar part of the vertebral 
column (Figs. 210, 211, and Pis., pp. 54, 262, 270, 278). 

The narrower and more conical thorax supports a 
shoulder-girdle of which the collar-bones are proportion- 
ately shorter and less curved than in the male. Sup- 
ported as these are by a narrower chest-wall and less power- 
fully developed muscles, they tend to occupy a horizontal 
position or may slope somewhat downwards. This imparts 



438 



Female Figure 



to the female neck an appearance of greater length (p. 376), 
and detracts from the squareness of the shoulder, which 
is so characteristic a feature of the male. The upper 
limb is to the trunk proportionately shorter than in the 
male. This is solely due, as Marshall has pointed out, to 





Fio. 208. Haunch-bone (03 in- 
noiuinatum) of male seen from the 
outer side ; it is represented as 
articulated with the sacrum. 



Fia. 209. Haunch-bone (os inno- 
minatum) of female. Note that 
the female bone is more tilted for- 
ward than the male, as shown by 
the relation of the points s and e 
to the dotted vertical line. 

/. Anterior inferior iliac spine. 

g. Acetabulum (hollow for bead of tbigh- 

bone). 
i. Posterior superior iliac spine. 
j. Spine of ischium. 
I. Tuberosity of ischium. 
a. Spine of pubis. 

a (limTence in the length of the humerus, that of the 
female being proportionately shorter than that of the 
male. 

Tho Ixjncs of the log and thigh are also proportionately 
HiiortcT than those of the male. In women the length of 
tbo leg U)udb to vary much more than the length of the 



a. Iliac portion of the innominate bone. 
h. I'ubic |KjrtJon of the innominate bone. 

c. Ijkihiftl i>ortiou of the innominate 

bone. 

d. Iliac cregt. 

«. Aut«riur Muperior iliac spine. 



I 
I 



Female Figure 



439 



thigh. The length of the lower limbs tends to vary more 
than the length of the trunk. Thus, when seated at table 





Fig. 2IO. 



Fig. 211. 



Figs. 2IO, 211, show the influence of the pelvic obliquity on the 
figure of the male and female. In Fig. 210 the pelvis is tilted further 
forward than in the male, Fig. 211, as will be seen by noting the position 
of the anterior extremity of the iliac crest (anterior superior iliac spine). 
As a result of this the lumbar curve is more pronounced in Fig. 210 
than in Fig. 211. This reacts on the outline of the figure, the curves 
being more pronounced in the female than in the male. 



it is very difficult to form an estimate of the heights of 
different individuals, as the lengths of the trunks are not 



^o Proportions of Female 

liable to such great variations as the lengths of the legs. 
It is only when the sitters rise from their chairs that we can 
form an accurate comparison, the difference in height being 
mainly due to differences in limb length. The patella is 
narrower in the female, and the foot is proportionately 
shorter ; it is also narrower relatively to its length. 

The head in the female is smaller absolutely and pro- 
portionately than in the male, though it is stated to be 
relatively higher. The sexual differences of the skull 
have been already described (p. 388) and need not here be 
repeated. Though statements are made to the contrary'-, it 
is often a matter of difficulty to determine whether a skull 
is that of a male or female, and in some cases the most 
expert anatomists will decline to express a decided opinion. 
For all practical purposes the rules already laid down 
for apportioning the several parts of the male figure may 
be employed in drawing the female so far as they apply 
to height, bearing in mind always that the trunk in 
woman is somewhat longer proportionately than in the 
male. This causes the centre of the figure to fall a little 
above the symphysis pubis instead of immediately below 
it, as in the male. Again, the arm in woman is propor- 
tionately shorter than in man. The tips of the fingers 
should barely reach the middle of the thighs, and, owing 
to the fact that the difference in length of the limbs is due 
to a difference in the proportion of the humerus, the upper 
ann should bo slightly shorter, and the elbow placed 
a fraction higher than in the male. In regard to the lower 
limbs, though proportionately shorter than in the male, 
the dili^.Tonco i.s not great, and length of limb tends to 
enhance the elegance of the figure. In this respect sculptors 
are apt to unduly emphasize the length of the legs, but 
as the results are much more pleasing from an aesthetic 
stand |)oiut than the opposite defect the question may well 
bo left to the individual i'ancy of tho artist. As the foot 



Proportions of Female 441 

is relatively shorter in the female than in the male, we 
find that a woman's height measures about 7 foot lengths, 
whilst that of a man is about 6-J. 

It is when the width of the * figure is considered that 
the distinctions between the sexes are most marked ; 
these are associated with differences in the form of the 
osseous framework, particularly the chest-wall and pelvis. 

Taking into consideration the height of the female, 
which, on the average, is less than that of man by about -^^ 
of his height, we find that the shoulders are not only 
absolutely, but also proportionately to the height, narrower 
than in the male. 

In man the width of the shoulders is about 2 heads 
or over, that is to say it is somewhat more than one-quarter 
of the height. In woman the width is equal to one-quarter 
of the height or a little less. 

The width of the hips in man should not exceed the 
width of the chest measured from the fold of one armpit 
to that of the opposite side, when the arms are hanging ; 
or, to put it in another way, if we drop two per- 
pendicular lines from the folds between the arm and 
the great pectoral muscles these lines should includs 
between them the maximum width of the hips. In tho 
female it is otherwise, for such lines will not be sufficiently 
far apart to include the width of the hips. How then 
are we to apportion the width of the hips in the female ? 
A rule sufficiently accurate for all practical purposes is 
the following : — Make the width of the hips equal to the 
distance between the fold of the armpit on one side and 
the outer side of the shoulder on the opposite side. Ex- 
pressed in a different way, the width of the hips in the 
male is equal to the width across the shoulders minus 
the two arms. In the female the width across the hips is 
equal to the width across the upper part of the chest i)lus 
the thickness of one arm. 



^^2 Proportions of Female 

The reader will recollect that in describing the deltoid 
(p. 135) it was pointed out that the greatest width of the 
shoulders did not overlie the heads of the humeri, but 
lay at a somewhat lower level, a level which was seen 
to correspond pretty accurately with that of the anterior 
fold of the armpit. 

Again, it is important to note that the maximum hip- 
width differs in its level in the two sexes ; as we have 
seen (p. 308), the greatest diameter in the male is opposite 
the level of the trochanters, whereas in the female it is 
somewhat lower, lying on a level with the fold of the 
buttocks posteriorly (Pis., pp. no, 142, 216). In the female, 
not only is the maximum width of the hips greater than 
the upper thoracic diameter, but the width of the figure 
taken on a level with the points at which the iliac crests 
reach the sides is also greater. This contrasts with the 
condition in the male, in whom this diameter, which is of 
course less than the maximum hip-width, must also be 
considerably less than the chest- width taken in the manner 
described above. 

The hip-width in women is not only greater in propor- 
tion to the height than in men, but is absolutely greater 
than in males of the same height. The depth of the 
f«5nialo figure is less in all its diameters, if we except 
the region of the buttocks. There, owing to the greater 
* obliquity' of the pelvis, the more pronounced backward 
thruHt of the sacrum, and the increased amount of fat, 
the width irom before backwards is absolutely greater than 
in tho male. The abdominal wall is more rounded, and the 
thighs are pro])ortionatoly thicker from back to front 
(I'ls.. pp. 86, 104, 124, 262, 318, 434) 1. 

' For further details in regard to the proportions of the adult the 
oludi-nt is r.'ferred to a work entitled A Rule of PropoHion for the Human 
yiyure,ly the late I'volesBor John Mai shall. Smith, Elder & Co., London, 
187 V. 



Proportions of Female 443 

The effects of habit and exercise on the form of the 
abdominal wall must not be overlooked. In a girl of 
athletic build, or in one who has indulged in gymnastic 
exercises, the muscles of the abdominal wall are better 
developed, and in consequence the roundness of the abdomen 
is less marked. This is well shown in the plate, p. 438, which 
represents a model of active habits, who professes never to 
have worn corsets ; a comparison of this figure with that 
displayed on the plate, p. 86, will at once illustrate the differ- 
ence between the two types referred to. 

The surface forms of the female have been already 
sufficiently described, and the points in which they differ 
from the male may be ascertained by consulting the 
chapters under which the various portions of the body 
have been discussed. 

It only remains to say a few words concerning the 
remarkable changes which take place in the proportion of 
the human figure from birth to adult life. 

The most striking feature about a child at birth is the 
large size of its head. The entire length of the child, 
including its trunk and legs, is a little over 4 heads as 
contrasted with 7J in the adult. The legs themselves only 
measure a little more than a head in length, whilst the 
trunk, including the head, measures 3 heads as compared 
with 4 in the adult. 

At birth the head is just about half the height of the 
adult head, so that the remainder of the child's length, 
which equals 3 infants' heads or i^ adult heads, must grow 
about four times as rapidly to make up the adult proportion 
of 6 1 heads which it ultimately attains. 

Attention has already been called to the fact (p. 389) 
that in the child the face is small proportionately to the 
brain-case. During growth, coincident with the changes 
already referred to, the face gradually enlarges till it attains 
the adult proportions. 



^.^ Proportions of Child 

The relation of the size of the head to the trunk at 
different periods of life may best be expressed in tabular 

form. 

At birth, trunk including head = 3 heads. • 
At 9 years, trunk „ „ = si heads. 

At 15 years, trunk „ „ = 3I heads. 

At 25 years, trunk „ „ = 4 heads. 

With reference to the proportion of height at different 
periods to that of the adult, it is found that — 

Height at birth = about two-sevenths of adult. 
Height at 3 years = one-half of adult. 
Height at 10 years = three-quarters of adult. 

The position of the central point of the figure gradually 
falls lower as life advances ; this depends, of course, on the 
increase in the length of the legs. 

At birth the centre is a little above the navel. 

At 2 years the centre is at the navel. 

At 3 years the centre is level with the iliac bones. 

At I o years the centre is level with the trochanters. 

At 13 years the centre is at pubis. 

In the adult the centre is at the arch of pubis (male). 

The growth, however, is not uniform throughout. As 
regards the torso, the .parts above and between the nipples 
j^row more rapidly than those which lie between the 
nipples and navel. In regard to the limbs at birth, the 
upper arms, legs between knee and ankle, and feet are all 
of about equal lengths. 

In the uppf3r extremity the length of the hand is a little 
more than the length of the fore-arm. The hand doubles 
lU length about the age of six, and trebles it between that 
and adult life. 

The upper limb in the adult is 3^ times the length of the 
infanfH ut birth, and of its different segments the fore-arm 
KrowH most rapidly. In the case of the lower extremity 



. Growth . 445 

the increase in length is very remarkable. In the adult 
it attains a length equal to fiYQ times its original measure - 
merit. Its rate of growth may be indicated as follows, 
measured from the fork to the sole of the foot : — 

At 3 years the lower extremity = twice its original length. 

At 12 years the lower extremity = four times its original length. 

At 20 years the lower extremity = five times its original length. 

The thigh grows proportionately longer and quicker than 
the other segments of the limb. 

The above details are sufficient to lay stress on the 
necessity of strict attention to the details of the model 
when representing youth and childhood. We have ad- 
mirable examples of this in the antique, where in the earlier 
examples of Greek art we find an utter lack of appreciation 
of youthful forms. Whether this was due to a want of 
knowledge is difficult to say ; yet the fact remains that the 
figures of the youths in the Laocoon are not those of boys, 
but are like small men. So also the figure of a youth 
praying, the author of which is unknown, has none of 
the attributes of youth, but displays all the bodily pro- 
portions of an adult. The figure in the arms of Zeus 
has none of the appearances of a child, but resembles more 
a mannikin. 

Apart altogether from the proportions of infancy and 
youth, about which, if he needs more information, the reader 
may consult the classic work of Quetelet^ the student 
will recognize how much the surface forms are modified 
by the abundant layer of fat which underlies the skin 
of a healthy infant. He will find here creases and folds of 
great depth overlying the joints and crossing the lines 
of flexure of the skin. Again, the dimpling of the skin 
in other situations may be the only indication of the 
existence of deeper structures. These it is not our intention 

it 
^ Anihiopometrief x^iir Ad. Quetelet. C. Muquardt, Cruxelles, 1870. 



^6 Old Age and Decay 

to discuss. The reader, if he has had the patience to study 
the previous pages, will have appreciated the conditions 
upon which these forms depend, and, having this know- 
ledge, can safely be trusted to select from the model only 
those details which are in harmony with the spirit of his 
design. 

Only a passing reference need be made to the changes 
due to the natural processes of decay. The softer tissues 
are the first to suffer. The absorption of the subcutaneous 
fatty layer leaves the skin loose and wrinkled. The wasted 
muscles cover but imperfectly the bony framework, and 
hence the outline of the skeleton is rendered more pro- 
minent on the surface of the body. The forms which were 
characterized by depressions and furrows in the prime 
of life are now> revealed as prominences and ridges. As 
examples take the anterior superior iliac spine, the iliac 
crests, the breast-bone, and the spines of the vertebrae. 
In addition, the weakened muscles are no longer able 
to perform efficiently their functions. Especially is this 
the case in regard to the back-bone. The habitual stoop 
of the aged is but an indication of this loss of power. As 
was pointed out in Chapter I, the aged are passing through 
a stage akin to that of childhood ; for now, as then, they 
have to seek support by the aid of the arms. The bones 
too undorgo a slow process of atrophy ; but the most marked 
rhangjjs in them are seen in the face, where the shedding 
of the teeth has led to an alteration in the form of both 
the upprT and lower jaws. The eyes also have sunk more 
deeply in their sockets, and, though at times under the 
infiuonco of excitement they are brigjit and clear, they lack 
a« a rule the lustre and brilliance of youth. These changes 
ttn^ hut the outward indication of processes which must 
Hlowly but surely end in death. 



APPENDIX 

For the sake of those of my professional brethren who may 
be asked to deliver courses of lectures on anatomy in art 
schools, I have introduced three illustrations as examples of 
the standardof excellence to which they may reasonably expect 
their pupils to attain after diligent and intelligent study. 

The examples supplied are a selection from the answers 
given to the following question in a recent examination : 
' Make a drawing, from whichever standpoint you choose, of 
a man in the act of throwing a cricket ball. The sketch 
must display the main features in the construction of the 
figure as regards bone and muscle.' 

As an examiner of some little experience, I am convinced 
that the best method of examining art students in anatomy 
is by setting them some such question, avoiding if possible 
a position which has been already anatomized in any of the 
current textbooks, and taking care also that the pose indi- 
cated does not closely resemble that of any of the ' antiques ' 
which the students may have been required to anatomize in 
their school course. 

In this way the repetition of a diagram committed to 
memory is avoided, and the student has an opportunity of 
displaying an intelligent application of the facts which he 
has learnt. No doubt the test is a severe one, since all the 
details are necessarily furnished from memory, though be it 
noted the candidate is permitted to answer the question 
without the additional burden of a scientific nomenclature. 
It matters not whether he knows the name of every pro- 
cess or muscle, provided he is acquainted with their correct 
form and disposition. 

The examples given may be regarded as a type of the 
work of the better class of student ; and speaking as an 
anatomist, and an anatomist only, they serve to illustrate 
what one may regard as the most satisfactory application 
of anatomy to figure construction. 

The illustrations, which are of course reproductions on a 



448 




449 




Gg 



45° 



Appendix 



reduced scale of the original drawings, may also be taken as 
examples of the methods most usually employed in answering 
such questions, viz. pencil, pen and ink, and a combination of 
wash and crayon. 




Such work, J hold, is the best answer to those who deny 
the utility of an acquaintance with anatomy as part of the 
education of the figure draughtsman or sculptor. 



INDEX 



Abdominal muscles, action of, 83. 
Abdominal wall, anterior, 67. 

aponeuroses of, 69. 

contours of, 74. 

form of, in female, 79. 

influence of movements on contours 
of, 84. 

limits of, 67. 

muscles of, 69. 
Abductor hallucis muscle (abductor 

of the great toe), 351. 
Abductor indicis muscle, 231. 
Abductor minimi digiti muscle, 233. 
Abductor minimi digiti muscle (ab- 
ductor of the little toe), 351. 
Abductor pollicis muscle, 229. 
Acetabulum, 244, 249. 
Acromion process of scapula, 97. 
Adam's apple, 365. 
Adductor brevis muscle, 299. 
Adductor longus muscle, 299. 
Adductor magnus muscle, 299. 
Adductor muscle of thigh, 293, 299. 

action of, 301. 
Adductor pollicis obliquus muscle, 

229. 
Adductor pollicis transversus muscle, 

230. 
Air sinuses, 387. 
Anconeus muscle, 175. 

i-elation to surface forms, 176. 
Ankle, the, 321. 

annular ligaments of, 327. 

internal annular ligament of, 340. 
Ankle-joint, 322, 325. 
Aponeuroses, 69. 
Aponeurosis, epicranial, 408. 
Arches of the foot, 345. 



Arm, femnle, form of, 242. 

proportion of, 242. 

superficial veins of, 217. 
Armpit, 145. 

Astonishment, expre'-sion of, 424 
Astragalus, 323. 
Atlas vertebra, 360. 
Auditory meatus, external, 399. 
Axilla, 128. See Armpit. 
Axis vertebra, 360. 



B. 

Back, surface forms of, difference 
between male and female, 144. 

form of, and buttock in the female, 
271. 
Back-bone, curves of, 37 ; in adult, 3 ; 
in infant, 3. 

position of, in man. 5 ; in animals, 5. 
Ball of little finger. 190, 332. 

of thumb, 190, 228. 
Band of Richer, 309. 
Biceps cubiti, relations to surface 

form, 172; action of, 173. 
Biceps flexor cruris muscle. 302. 
Biceps flexor cubiti muscle, 169. 
Biceps muscle of the arm, 169. 
Bicipital groove, 118. 
Bicipital tubercle, 156. 
Blushing, 407. 
Bonos, classification of, 24. 

efface, 391. 

flat, 25. 

of the foot, 322, 343. 

of fore-arm, 151; rel.ition to surface 
forms, 179. 

of tlic leg, 282, 320 

as leverr, 25. 



452 



Index 



Bones, long. 24. 

proportions of the principal long 

. bones, 434. 

protective, 25. 

of the wrist, 186. 188. 
Uraehialis anticus muscle, 168. 

relations to surface form, 169. 

action of, 169. 
Mr<\i^t-bonc, 17, 61. 
Breasts, male, 130. 

ft'inale, 131. 
liuttock, surface furms of, 277, 278 ; 
in female, 279 

transverjie furrow of, 268. 
Buttocks, 12. 

C. 

Calf, muscles of, 333. 

action of, 336. 
Calvaria, 384. 
Cantlius, oxtf-rnal, 404. 

internal, 404 
Cnpitellum of jiuinoius, 151. 
Carpal hones, 186, 188. 
Cartilage, articular, 27. 
Cervical fascia, deep, 373. 
Choek-bones, 391. 
Chest, form of, 17. 

cavity, 17. 
CIie«t-walI, 17. 26, 56. 
Cliild, proportions of, 443 
Chin, tlie, 398. 

Clavicle, 18, 89. .SVc Collar-bone. 
^^'*'<'yx, 33- 
<'ollar-honn, 18, 89. 

r»oiiition of. in man and woman, loi. 

hoUowM al»ovo the, 371, 
ComproHHor naris muscle, 414. 
Ciinjunctivn, the, 405 
Contoum of tho nock. 375. 

C*.r»ro.brarhinliH mUMclc, 147. 
•rlion of, 1 49. 
influence on nurfaco forma, 149. 

';'"*'"••'• Pf"*-*'"" of Hrni.ula, 99. 
Corn<'a, 404. 

Coronold f.,«Mi of humerus, 159. 

""i'lnolrhoflowMJaw, 39, 

-.lpr.H«..Kofl.,w..rjaw,39,. 
of ulna, 153 



Corrugator supercilii muscle, 409. 
Crnnial box, 386, 
Cranium, 384, 389. 
Crureus muscle, 293. 
Cuneiform bones, 323. 



Decay and old nge, changes due to, 

446. 
Deltoid eminence, 134. 
Deltoid impression, 118. 
Deltoid muscle, 133, 140. 
action of, 136. 

relation to surface form, 135. 
D.epressor alae nasi muscle, 415. 
Depressor anguli oris muscle, 417. 
Depressor labii inferioris muscle, 

418. 
Determination, expression of, 423. 
Devotion, expression of, 422, 
Diaphragm, 67. 
Diploe, 387. 
Disdain, expression of, 423. 



E. 



Ear, tho, 400. 

Elbow, bent, form of, 214. 

contours around, 213. 

depression behind the, 205. 

hollow in front of, 210. 
Klbow-joint, 149, 157. 

bonos of, relation to surface forms, 
164. 

movements of, 157, 161. 
Ensiform cartilage, 64. 
Epicanthus, 403. 
Epicranial aponeurosis, 408. 
Erector spinae muscle, 40-1. 

surface contours of, 43. 
Erectores spinae muscles, 6, 143. 
I'^roct j)Osture, mechanism of, 259. 

mechanism of knee-joint in relation 
to, 291. 
Expression, 405. 

habitual, 425. 

influence of blood-vessels on, 406. 

muscles of, 408. 



Index 



453 



Extensor carpi radialis brevior 

muscle, 20I. 
Extensor cai'pi radialis longior muscle, 

20I. 

Extensor carpi ulnaris muscle, 202. 
Extensor communis digitorum 

muscle, 204. 
Extensor longus digitorum pedis 

muscle, 330. 

Extensor muscles of the thumb, 206. 

Extensor muscle of the toes, long, 329. 

short, 350. . 

Extensor ossis metacarpi pollicis 

muscle, 207. 
Extensor primi internodii pollicis 

muscle, 207. 
Extensor proprius hallucis muscle 

(specialextensorofgreattoe),33o. 
Extensor secundi internodii pollicis 

muscle, 208. 
External oblique muscle of abdominal 

wall, 69, 73, 142. 
Eyeball, movements of, 412. 
Eyebrows, the, 413. 
Eyelashes, the, 413. 
Eyelids, the, 403, 413. 
Eyes, the, 402. 
in expression, 412. 



Face, bones of, 391. 

skeleton of, 384. 
Facial anglej the, 392. 
Fascia, cervical, 373. 

of upper arm, 167. 
Fear, expression of, 424. 
Female, proportions of, 435. 
Female figure, characteristics of, 435. 
Femur, 11, 254. 

condyles of, 15, 255, 280. 

obliquity of, 255. 

trochanter major of, 272. 

trochanters of, 254. 
Fibro-cartilago, triangular, of wrist, 

183. 
Fibula, 15, 282, 285, 320. 

head of, 285 ; relation to surface, 
286. 

styloid process of, 286. 



Finger, little, muscles of, 232. 
Fingers, the, 236. 

bones of, 186, 225. 

common extensor muscle of the, 
204. 

joints of, 226. 

length of, 239. 

movements of, 226, 240. 

superficial flexor muscle of, 198. 
Flank, the, 80. 

length of, in female, 436. 
Flexor brevis digitorum pedis muscle 

(short flexor of the toes), 352. 
Flexor brevis minimi digiti muscle, 

232. 
Flexor brevis pollicis muscle, 229. 
Flexor carpi radialis muscle, 196. 
Flexor carpi ulnaris muscle, 196. 
Flexor sublimis digitorum muscle, 

198. 
Flexor longus hallucis muscle (long 

flexor of great toe), 332. 
Flexor muscles of fore-arm, 168. 
Flexure of thigh, line of, 78. 
Fold of the groin, 68, 76. 
Foot, 15. 

arches of the, 15, 345. 

bones of, 322, 343. 

dorsum of the, 349. 

female, 356. 

interossei muscles of, 351. 

muscles of, 351. 

sole of the, 353-4. 
Foramen magnum, 386. 
Fore-arm, 178. 

action of muscles of, 220. 

bones of, relation to surface forms, 
179. 

flexor muscles of, 168. 

influence of position on form of, 
211. 

muscles of the, 191. 

summary of muscles of, 208. 

surface contours of, 209. 
Forehead, the, 388, 
Frontal bone, 26, 387. 
Frontal eminences, 388. 
Frontal sinus, 388. 
Furrow, naso-labial, 419. 

ulnar, 154, 203. 



454 



Index 



G. 

Gastrocnemius muscle, 334. 

Gfcbturu and expression, 420. 

Glands, salivary, 370. 

Glenoid fossa, 119. 

Gluteal fold, 268. 

Gluteal ridge, 267. 

Gluteus maximus muscle, 248, 268. 

action of, 272. 
Gluteus medius muscle, 276. 

action of, 276. 
Gracilis muscle, 299, 300. 
Grief, expression of, 422. 
Groin, the, 76. 

fold of, 68, 76, 277. 

furrow of, in female, 437. 
(irowth, 444. 
Gullet, 364. 

n. 

Ilani, the, 304, 341. 
llaiji.'jtriiig muscles, 302. 

a<;lion of, 305. 
Hamstring tendons, 304, 342. 
Hand, 20, 221. 

back of, 237. 

dorsal interossei muscles of, 239. 

palm of, 233. 

skeleton of, 222. 

hiimmary of structure of, 241. 
Iluiinch-boue, 10, 67, 244. 
Iluad, hizo of, 389-90. 
IlcHil-bone, 15, 3:^4. 
Hflplenhnuss, expression of, 424. 
llip joint, 357. 

Uiuvenientu of, 264. 
llip-width, 308. 

diff««rencch in male and female, 253. 

in fuiiudu, 44 J. 

ill limn, 44J. 
Hollow U-lnnd the knee, 304, 341. 

*>t thigh, 399. 
Iff.Uuw. ttbovo tho c<jllur-l)onc, 371. 
ll<<rroi, exprohHJon of, 4^5. 
II)i< klu-biiliu, 333. 
HuiiiuruM, 17, ii-;. 

coiiUyluN of, 118, 150. 

coruuuid (uMtt of, 159. 



Humerus, lower end of, 149. 

olecranon fossa of, 159. 
Ilyoid bone, 364. 



I. 



Iliac crest, 246. 

relation of, to surface, Go. 
Iliac fossa, 247. 
Iliac furrow, 80. 
Iliac spines, 68, 247. 

anterior inferior, 259. 
' anterior superior, 68 ; position of 
in relation to surface, 277. 

posterior superior iliac spine, 41. 
Iliacus muscle, 299. 
Ilio-femoral ligament, 259. 

influence on obliquity of the pelvis, 
261. 
Ilio-tibialband, 275. 
Ilium, 67, 244. 

Ill temper, expression of, 422. 
Iiidignation, expression of, 423. 
Infra-spinatus muscle, 136, 141. 

action of, 137. 

influence on surface form, 137. 
Infra-spinous fossa, 96. 
Innominate bone, 244. See Ilaunch- 

boue. 
Instep, the, 323, 354. 
Interclavicular ligament, 92. 
Intermuscular septa of upper arm, 
168. 

relation to surface forms, 176. 
Internal oblique muscle of abdomi- 
nal wall, 69. 
Interossei muscles of the foot, 351. 

of hand, 231. 

dorsal, of hand, 239. 
Intervertebral disks, 29. 
Iris, the, 404. 
Ischium, 67, 244, 248. 

tuberosity of, 248 ; influence on 
surface form, 273. 

J. 

Jaw, lower, 384, 394. 
articulation of, 394. 
chang(!S due t<t ag»;, 396, 
condyle of, 394. 



Index 



455 



Jaw, coronoid notch of, 394. 

coronoid process of, 394. 
Joints, classification of, 28. 

immovable, 29. 

movable, 28. 

structure of, 27. 
Jugular vein, external, 374, 



K. 

Knee, hollow behind the, 304, 341. 

surface forms of, 311. 
Knee-joint, 286. 

crucial ligaments of, 288. 

hyper-extension of, 292. 

lateral ligaments of, 289. 

locking of, 291. 

mechanism of, in relation to erect 
posture, 291. 

movements of, 291. 

posterior ligament of, 289. 
Knee-pan, 284. See Patella. 
Knuckles, 223, 226, 236. 



L. 

Larynx, 364. 

Latissimus dorsi muscle, 113, 123, 
140. 

action of, 127. 

relation to surface form, 125. 
Laughter, 422. 
Leg, the, 12, 320. 

bones of the, 282, 320. 

in female, 438. 

form of, in female, 343. 

intermuscular septa of, 327. 

muscles of, 327. 

straightness of, 310. 

superficial veins of, 357. 

surface contours of, 339. 
Levator alae nasi muscle, 414. 
Levator anguli oris muscle, 417. 
Levator anguli scapulae muscle, 107. 

action of, 109. 
Levator labii superioris et alae nasi 

muscle, 416, 
Levator labii superioris proprius 
muscle, 416. 



Levator menti muscle, 398, 418. 
Levator palpebrae superioris muscle, 

412. 
Ligament, great sacro-sciatic, 267. 

ilio-femoral, 259. 

intercl*ivicular, 92. 

orbicular, 181. 

Poupart's, 68, 248. 

Y-shaped, 259. 
Ligaments, 27. 
Ligamentum nuchae, 362. 
Ligamentum patellae, 284. 
Limb girdles, 7. 
Limb, lower, in female, 439. 
Linea aspera of femur, 255. 
Lineae semilunares, 74. 
Lineae transversae, 74. 
Lips, the, 401. 

Little finger, ball of, 190, 232. 
Lower limb, skeleton of, 13, 245. 
Lumbar aponeurosis, 69, 123. 



M. 



Malar bones, 391. 
Malleolus, external, 285, 320. 

internal, 285, 320. 
Mammary gland, 130. 
Mandible, 384. 
Masseter muscle, 395. 
Mastoid process of temporal bone, 368, 

399- 
Metacarpal bones, 186, 222. 

Metatarsal boneg, 323. 

Mouth, the, 401. 

the, in expression, 419. 

influence of form ol", on expression, 

415- 
muscles of the, 416. 
Muscles, direct action of, 102. 
indirect actiun of, 103. 
of back, summary of, 140 ; relations 

to surface forms, 141. 
of the calf, 333 ; action of, 336. 
of expression, 408. 
of the foot, 351. 
of tlie forearm, 191. 
of the leg, 327, 
of the mouth, 416, 
of the neck, 361. 



45^ 



Index 



Muscles of the nose, 414. 
of tlie thigh, 293. 



Xasal bones, 398. 
Nasal cartih\ges, 399. 
Xaso-labial furrow, 419. 
Navel, 74. 

Navicular bone, 323. 
Neck, the, 359. 

contours of, 375. 

deep structures of, 363. 

female, 438. 

length of, 375-6. 

movements of the, 360 ; influence 
on surface form, 376, 

muscles of the, 361. 

pit of, 92, 399. 

and shoulder, 383. 
Nipple, position of, 13:. 
Nose, 398. 

alae of, 402. 

muscles of the, 414. 



0. 

Obliquity of pelvis, 261. 
Oliturator foramen, 246. 
Occipital bone, 387. 

external protuberance of, 385. 

i»;ip«'rior curved line of, 398. 
Occipito-frontalis muscle, 408. 
Odontoid process of axis, 360. 
OeikjphagUH, 364. 
Old UK", changes due to, 446. 
Olecranon f.ma of humerus, 159. 
OK-cranon process of uhui, 153. 
Omohyoid muscle, 371. 
OpiKimnii minimi <ligiti muscle, 232. 
OpiKiHonii polIi.iM niUHclo, 229. 
Orbirular liKam«iit, iBi. 
OrbicnlnriH oris nuHch,, 416. 
Orblcul.ri* pulpobi ai urn muscle, 4 , , 
OrbiU, ih.., 398. 
0«cah:iii, 15, 3^4. 

On innominuiurn, 10. .See IlauMd, 
Ixihe. 



P. 

Palm, the, 233. 

lines of, 234. 
Palmar fascia, 233. 
Palmaris brevis muscle, 236. 
Palmaris longus muscle, 197. 
Parietal bones, 26, 387. 
Parietal eminences, 388. 
Patella, 284, 287. 

ligament of, 284, 287. 
Pectineus muscle, 299. 
Pectoralis major muscle, 127. 

action of, 130. 

relation to surface forif , 128, 
Pectoralis minor muscle, 114. 

action of, 114. 
Pelvic cavity, 244. 
Pelvic girdle, 7, 243. 
Pelvis, 10, 244, 250. 

differences between male and 
female, 250. 

female, 435. 

obliquity of, 261 ; effect on curves 
of back, 262 ; effect on thigh, 264 ; 
in female, 437. 

position of, 250. 
Peroneus brevis muscle, 331. 
Peroneus longus muscle, 331. 
Peroneus tertius muscle, 330. 
Phalanges, i86, 225, 323. 
Pisiform bone, 190. 
Pit of neck, 64, 92, 399. 

of stomach, 64. 
Plantar fascia, 353. 
Platysma myoides muscle, 374. 
Pomum Adami, 365. 
Position of collar-bone in man and 

woman, lox. 
Poupart's ligament, 68, 248. 
Pronation, 153, 178. 
Pronator muscles, 193. 
Pronator radii teres muscle, 193, 195. 
Proportion, 427. 
Proportions of child, 443. 
of the long bones, 434. 
relative, of niale and femalo, 435. 
Psoas muscle, 299. 
Pubis, 68, 247. 
crest of, 248. 



I 

I 

\ 



I 



Index 



457 



Pubis, spine of, 68, 248. 

symphysis, 10, 68, 244, 248. 
Pupil, the, 404. 
Pyramidalis nasi muscle, 409. 



Q. 



Quadratus menti muscle, 418. 



R. 



Eadial extensor muscles, 201. 
Radius, 20, 151, 156. 

liead of, 156. 

lower end o'", 187. 

sigmoid cavity of, 183. 

styloid process of, 157, 187. 
Rage, 423. 

Recti abdominis muscles, 66 73. 
Rectus abdominis muscle, 70. 
Rectus femoris muscle, 296. 
Reflection, expression of, 422. 
Rhomboid muscles, 107, 141. 

action of, 109. 

influence on surface form, loB. 
Rib cartilages, 57. 
Ribs, 56. 

false, 59. 

floating, 59. 

true, 57. 
Richer, band of, 309. 
Risorius muscle, 417. 



Sacro-sciatic ligament, great, 267. 
Sacro-vertebral angle, 37. 
Sacrum, 7, 33, 244, 249. 
Salivary glands, 370. 
Saphenous veins, 358. 
Sartorius muscle, 296, 297. 

action of, 298. 
Scaphoid bone, 190. 
Scapula, 16, 93. See Shoulder-blade. 

acromion process of, 97. 

coracoid process of, 99. 

movements of, 142. 

rotation of, 115. 

spine of, 96. 
Scapular triangle, 141. 



Sclerotic coat of eyeball, 404. 
Semimembranosus muscle, 303. 
Semitendinosus muscle, 302. 
Serratus magnus muscle, in. 

action of, 114. 

influence on surface forms, 113. 
Sesamoid bo'ne, 230, 
Sesamoid bones of foot, 345. 
Shin, the, 284. 

Shin-bone, 12, 282. See Tibia. 
Shoulder-blade, 16, 93. See Scapula. 
Shoulder-girdle, 7, 16, 89. 

adaptation of, to chest-wall, 99-100. 

relation of, to surface, loi. 
Shoulder-joint, 119. 

movements of, 120. 
Shoulders, squareness of, 101-2. 

width of, 135. 
Shyness, expression of, 423. 
Sigmoid cavity of radius, 183. 
Sigmoid notch, greater, 153. 

lesser, 154. 
Sinuses, air, 387. 
Skeleton, definition of, 24. 
Skull, the, 20, 384. 

base of, 386. 
Sneering, 423. 
Soleus muscle, 333. 
Sphenoid bone, 26, 387. 
Spinal column, 5. 
Splint-bone, 285. See Fibula. 
Sterno-mastoid muscle, 367-8. 

action of, 373. 
Sternum, 17, 59. See Breast-bone. 
Stomach, pit of, 64. 
Styloid process of radius, 157, 187. 

of ulna, 154, 155, 183, 187. 
Suffering, expression of, 421. 
Summary of the muscles of the back, 
140. 

of muscles of the fore-arm, 208. 

of structure of hand, 241. 
Supination, 153, 178. 
Supinator longus muscle, 193, 199. 
Supinator muscles, 193. 
Supra-condyloid ridges, 150. 
Stipra-spinous fossa, 96. 
Surprise, expression of, 424. 
Sustentaculum tali, 324, 
Sutures, 30, 387. 



458 

Sympliysis pubis, lo, 68, 244, 2^ 

Synovia, 28. 

Synovial membrane, 28. 



T. 



Tarsnl Itonr s. 322. 
Tomporal ]»one, 26, 3C4. 387. 

mastoid process of, 368, 399. 
Temporal fossa, 391. 
IVmporal muscle, 391. 
'romporo-maxillary articulation, 394. 
Tendo Achillis, 324, 334. 
Tendo oouli, 404. 

Tensor fasciae femoris muscle, 273. 
Teres major muscle, 139, 141. 
action of, 139. 

influence on surface form, 139. 
Teres minor muscle, 136, 139, 141. 
action of, 137. 

influence on surface form, 137. 
T«'rror, expression of, 424. 
Thiyh, tlio, 280. 

action of extensor muscle of the, 

296. 
addtu-tor muscles of, 293, 299. 
back of, surface forms of, 304. 
ritntours of, 308. 
fancia of, 293. 
ft-male, 437 ; form of, 306. 
flr-xor miiscb's of, 302, 
fold of lb«*, 277. 

form of the, 306 ; in flfxion, 31 1. 
hollow of, 299. 
inuKrh'd c»f, 293. 
Thich l>oiit>, M. 254, 280. .SecFcnnir. 
obliquity of, 255. 

pfm'iiion of, in male and female, 
ass. 
Thorarir cavity, 17. 
Thomx. 56. 
f«miih<, 65. 

lnflui»nro on Kurfae*- < f.tilcpiirs, 06. 
m^iYi»montii of, 65. 
Thumb, 337. 
ball of, 190, 228. 
««xt4«n«or inuHclcH fif tho, 207. 
wwimoid bonr<«t of, 330. 
•hort muHclcB of, 328. 



Index 



1 



Thumb, surface forms dependent on 

extensor muscles of, 207. 
Thyroid body, 364, 367. 
Thyroid foramen, 246. 
Tibia, 12, 282, 320. See Shin-bone. 

tubercle of, 284. 

tuberosities of, 282. 
Tibialis anticus muscle, 329. 
Toes, the, 354. 

long extensor of, 329. 

short extensor muscle of, 350. 
Trachea, 364. 
Transvei'salis muscle, 69. 
Trapezium, 190. 
Trapezius muscle, 105, 140. 

action of, 109. 

influence of, on surface, 106. 
Triangular fibro-cartilage of w^rist, 

183. 
Triangularis menti muscle, 417. 
Triceps muscle, 174. 

action of, 175. 

relation to surface forms, 174. 
Trochanter major, 272. 

relation of, to surface, 254. 
Trochanters of femur, 254. 
Trochlea, 151. 



u. 

Ulna, 20, 15T. 

coronoid process of, 153. 

head of, 155 ; relation to surface 
form, 188. 

lower end of, 155, 187. 
I olecranon process of, 153. 

relations of, to surface forms, 154- 

styloid process of, 154, i55> ^^3; 
187. 

upper end of, 153. 
Ulnar extensor muscle, 203. 
Ulnar furrow, 154, 203. 
Unciform bone, 191. 
Upper arm, 145. 

fascia of, 167. 

intermuscular septa of, r68. 
Upper limb, form of, in female, 
242. 

proportion of, 242. 

skeleton of, 20. 



I 



I 



Index 



459 



Vasti muscles, 293. 
Vastus externus muscle, 294. 
Vastus internus muscle, 294. 
Veins, colour of superficial, 218. 

external jugular, 374. 

saphenous, 358. 

superficial, of arm, 217 ; of leg, 357. 
Vertebra, articular processes of, 33. 

prominens, 39, 359. 

spinous process of, 33. 

transverse process ol, 33. 
Vertebrae, 5. 

cervical, 36. 

dorsal, 36. 

immovable, 33, 36. 

lumbar, 36. 

movable, 33, 36. 

thoracic, 36. 
Vertebral column, 5, 31. 

curves of, in adult, 3 ; in infant, 

3- 
movements of, 46, 
position of, in man, 5 ; in animals. 



Vertebral spines, relation to surface, 
37- 

W. 

Walking, first attempts at, 2. 
Windpipe, 364. 

Wrist, anterior annular ligament of, 
189. 

bones of, 186, 188. 

flexor muscles of the, 196, 

front of the, 219. 

posterif - annular ligament of the, 
205. 
Wrist-joint, 186. 

movements of, 191. 

triangular fibro-cartilage of, 183 



Y-shaped ligament, 259. 



Zygomatic arch, 391. 
Zygomatici muscles, 417. 



THE £KD 



THE LIBRARY 




THE UNIVERSITY OF 
BRITISH COLUMBIA 



University of British Columbia Library 

DUE DATE 



» . . _ 




ikir'n 1 9 Hi^ 




r 




rC ^'^* ■^.■.=- ^^r^. 








IAMf)b WC 




.,ftNl3HEC0 

































ET-6 BP 74-483 




--. 1 



i-INC ARTS 
LIBRARY 



.^dl^^K^^^Hfl